bluuebunny/crossref_metadata_2025 huggingface dataset:
Oviductal fluid counterbalances the negative effect of high temperature on sperm in an ectotherm model
Authors: Rossi N. , Lopez Juri G. , Chiaraviglio M. , Cardozo G.
Published: March 2021

Global warming is affecting biodiversity; however, the extent to which animal reproductive processes respond to predicted temperature increments remains largely unexplored. The thermal environment has a pronounced impact on metabolic rates of ectotherms; therefore, an interesting question to assess is whether temperature increase might affect specific reproductive mechanisms like sperm performance in ectotherms. Moreover, in many species, oviductal fluid (OF) is known to regulate and maintain sperm quality; however, the role of OF in relation to the effects of high temperature on sperm remains unclear. Our aim was to experimentally test the effect of increased temperature on sperm velocity, swimming path and percentage of motility in neutral conditions at ejaculation (without OF) and in female's reproductive tract fluid (with OF), in a social ectotherm lizard model, Tropidurus spinulosus, which has specific thermal requirements for reproduction. Our results suggest that a rising temperature associated with global warming (+4°C) affects negatively sperm dynamics and survival. However, OF ameliorated the harmful effects of high temperature. This is an important point, as this study is the first to have tested the role of OF in preserving sperm from a warmer pre-fertilization environment. These results contribute to our understanding of how thermal environment changes might affect post-copulatory reproductive mechanisms.

This article has an associated First Person interview with the first author of the paper.
Genome size influences adaptive plasticity of water loss, but not metabolic rates, in lungless salamanders
Authors: Johnson Benjamin B. , Searle Jeremy B. , Sparks Jed P.
Published: March 2021

Many expressions of phenotype, such as physiological performance, integrate multiple underlying traits to function. Linking component traits to adaptive physiology thus gives insight into mechanisms of selection acting on performance. Genome size (C-value) is a trait that influences physiology in multiple taxa by exerting a nucleotypic effect, constraining cell size and cellular physiology such that whole-organism mass-specific metabolism is reduced with increasing C-value. We tested for this mechanism of C-value function acting in lungless salamanders, plus an unexplored potential mechanism of C-value effects constraining water transport across the body surface to influence cutaneous water loss rates. We found no evidence for a nucleotypic effect on metabolic rates, but we demonstrate a relationship between C-value and water loss physiology. Under warmer experimental conditions, C-value was inversely correlated with water loss and positively correlated with resistance to water loss, which demonstrated adaptive plasticity at higher temperatures. We hypothesize that this pattern results from differences in cell size constraining diffusion and evaporation of water from the skin under warm conditions when cutaneous perfusion is reduced. Testing this hypothesis may confirm a previously unappreciated adaptive role for C-value variation in this group, and reveals the possibility that genome size influences physiological exchange across transport barriers more broadly.
High resolution ultrasonography of peripheral nerves in diabetic patients to evaluate nerve cross sectional area with clinical profile
Authors: Narayan Shamrendra , Goel Amit , Singh Ajai Kumar , Thacker Anup Kumar , Singh Neha , Gutch Manish
Published: March 2021

Objectives:

The aim of this observational study was ultrasound evaluation of peripheral nerves cross-sectional area (CSA) in subjects with probable diabetic peripheral sensorimotor neuropathy (DPN). CSA was analyzed with reference to clinical and nerve conduction study’s (NCS) parameters for early diagnosis and pattern of involvement.

Methods:

A total of 50 patients with probable DPN due to Type 2 diabetes and 50 age-matched healthy controls underwent sonographic examinations of ulnar nerve at the lower arm, median nerve proximal to carpal tunnel, the common peroneal nerve proximal to fibular head, tibial nerve proximal to the tarsal tunnel, and sural nerve at lower third leg.

Results:

CSA was increased in cases of DPN as compared to healthy controls. Area changes were more marked with demyelinating pattern. Probable DPN cases with normal NCS had significantly higher number of peripheral nerves showing increased CSA as compared to healthy control. A cut-off of >4 nerve thickening showed a sensitivity of 86 %, and specificity of 56%. The neuropathy pattern in the lower limb was axonal, whereas in the upper limb, it was demyelinating with the majority showing sonographic feature of associated compressive neuropathy.

Conclusion:

There is an increase in CSA of peripheral nerve in diabetic patients. It can be used as a morphological marker for classifying DPN with changes being picked up earlier to NCS abnormality. Clinical neurological presentation in probable DPN can also be due to compressive neuropathy in early phases, and ultrasound can be a useful tool.

Advances in knowledge:

Early pick up of DPN cases shall be useful for early therapy and motivating the patients to actively participate in the treatment. Morphological changes on ultrasonography precedes the electrodiagnostic change in DPN. Symptoms of DPN is not only due to metabolic changes but also compressive neuropathy.
Συσχέτιση των ιών των ανθρωπίνων θηλωμάτων με τον καρκίνο κεφαλής και τραχήλου στην περιοχή της Θεσσαλίας
Authors: Τσέα Μαλαματή
Published: March 2021

Στόχοι: Αξιολόγηση της κατανομής επιπολασμού και υποτύπων HPV σε πληθυσμό ασθενών με Ακανθοκυτταρικό Καρκίνωμα Κεφαλής και Τραχήλου (AKKT) στην κεντρική Ελλάδα και η συσχέτιση τους ως προς την συμβολή τους στην καρκινογένεση. Μέθοδοι: Δείγματα βιοψίας ενσωματωμένα σε παραφίνη από 90 ασθενείς με επιβεβαιωμένο AKKT μελετήθηκαν για την παρουσία διάφορων υποτύπων HPV μέσω PCR πραγματικού χρόνου. Επιπλέον, συνολικά 206 στοματοφαρυγγικά δείγματα υγιών ατόμων(ομάδα ελέγχου), τα οποία επισκέφθηκαν την ΩΡΛ Κλινική την ίδια περίοδο, εξετάστηκαν επίσης για την παρουσία υποτύπων HPV με τον ίδιο μοριακό προσδιορισμό. Αποτελέσματα: Ο καρκίνος κεφαλής και τραχήλου εντοπίζεται κυρίως σε τέσσερις διαφορετικές ανατομικές θέσεις: στοματική κοιλότητα, στοματοφάρυγγα, λάρυγγα και υποφάρυγγα. Η παρουσία HPV ανιχνεύθηκε σε 42,2% των δειγμάτων (38/90) στις παραπάνω ανατομικές θέσεις, ενώ ο επικρατέστερος υπότυπος ήταν ο HPV-16 (89,5%,34/38), ακολουθούμενος από τα στελέχη HPV-18 (2,6%), HPV-31(2,6%) και HPV-33(2,6%). Μεταξύ των δειγμάτων HPV (+) AKKT, τα περισσότερα προήλθαν από τη στοματική κοιλότητα (45%, 17/38) και το στοματοφάρυγγα (32%, 12/38). Από την άλλη πλευρά, από τα δείγματα σε υγιείς, βρέθηκαν 9,7% (20/206) θετικά στον HPV, ενώ οι πιο διαδεδομένοι υπότυποι ήταν οι HPV-31, HPV-56, HPV-45 και HPV-41. Επιπλέον, έξι δείγματα ήταν θετικά για περισσότερους υποτύπους. Η στατιστική ανάλυση έδειξε ότι οι ασθενείς με HPV (+) ήταν 7 φορές πιο πιθανό να έχουν AKKT [ OR 6.8, 95%CI 3.65-12.67, p <0,0005] και οι ασθενείς με HPV-16 (+) ήταν 124 φορές πιο πιθανό να έχουν AKKT [OR 124,5, 95% CI 16,67-929,3, p <0,0005]. Συμπεράσματα: Υψηλή επικράτηση του HPV ανιχνεύθηκε σε ασθενείς με AKKT στην κεντρική Ελλάδα, όπου κυριαρχεί ο HPV-16, ο οποίος παρουσιάζει στατιστικά σημαντικά διαφορά ως προς τον κίνδυνο καρκινογένεσης, p<0,0005. Παρουσιάζεται υψηλό ποσοστό επιπολασμού HPV (42,2%), το οποίο όμως είναι πολύ μικρότερο στην ομάδα ελέγχου, μόλις 9,7%, γεγονός που ενισχύει τη καταγεγραμμένη άποψη ότι η λοίμωξη από HPV προδιαθέτει στην εμφάνιση καρκίνου στην ανατομική περιοχή κεφαλής και τραχήλου. Καταδεικνύεται ακόμη, ότι ο αποικισμός και από τους άλλους υποτύπους του HPV, έχει στατιστικά μεγάλη σημασία ως προς τον κίνδυνο καρκινογένεσης, p<0,0005. Τέλος, ο αριθμός των ασθενών που ήταν καπνιστές και HPV+ βρέθηκε στατιστικά σημαντικά μικρότερος από τον αριθμό των ασθενών που ήταν καπνιστές και HPV-. Έτσι, φαίνεται να μην υπάρχει συνεργική καρκινογεννετική δράση της παρουσίας του HPV στα επιθηλιακά κύτταρα του ανώτερου αναπνευστικού, με την χρήση προιόντων καπνού από τον ασθενή, αλλά ο κάθε ένας λειτουργεί σαν ανεξάρτητος καρκινογεννετικός παράγοντας.
Phytochemicals With Anti 5-alpha-reductase Activity: A Prospective For Prostate Cancer Treatment
Authors: Azizi Aziemah , Mumin Nuramalina H , Shafqat Naeem
Published: March 2021

Prostate cancer (CaP) is one of the leading causes of death in men worldwide. Much attention has been given on its prevention and treatment strategies, including targeting the regulation of 5-alpha-Reductase (5αR) enzyme activity, aimed to limit the progression of CaP by inhibiting the conversion of potent androgen dihydrotestosterone from testosterone that is thought to play a role in pathogenesis of CaP, by using the 5-alpha-Reductase inhibitors (5αRis) such as finasteride and dutasteride. However, 5αRis are reported to exhibit numerous adverse side effects, for instance erectile dysfunction, ejaculatory dysfunction and loss of libido. This has led to a surge of interests on plant-derived alternatives that might offer favourable side effects and less toxic profiles. Phytochemicals from plants are shown to exhibit numerous medicinal properties in various studies targeting many major illnesses including CaP. Therefore, in this review, we aim to discuss on the use of phytochemicals namely phytosterols, polyphenols and fatty acids, found in various plants with proven anti-CaP properties, as an alternative herbal CaP medicines as well as to outline their inhibitory activities on 5αRs isozymes based on their structural similarities with current 5αRis as part of CaP treatment approaches.
El método fenomenológico en los seminarios de Zollikon de Martin Heidegger.
Authors: Carmine Fasolino Rubén
Published: March 2021

Este escrito trata de ser un aporte más a los estudios que han tratado la relación entre Heidegger y Freud. Apoyándose en otras lecturas -J. Derrida, J. Alemán y S. Larrierasondearemos algunos momentos de convocación mutua que, quizás, por un exceso de cercanía, no se pudieron percibir como tales. Del mismo modo trataremos de mostrar como Freud se inserta en la Modernidad a través de su peculiar concepción de síntoma como Kompromißbildung, un abordaje del fenómeno patológico que no puede desligarse de la temporalidad y el sentido en su génesis. De este modo también Freud concibe al sujeto -sin abordarlo temáticamente- en una unión inextricable de tres factores: la afectividad, la comprensión y el lenguaje.
Deterioro o enfermedad del lenguaje. Un diálogo entre Heidegger y el psicoanálisis.
Authors: Gómez Tirado Guillermo
Published: March 2021

Este trabajo pretende ser una aportación al posible diálogo entre Heidegger y el psicoanálisis señalando, por una parte, dos puntos esenciales. Primero, la necesidad de hacer relevante el diálogo mismo, esto es, justificar que ocurra. Segundo, dar cuenta de que aquello que justifica el diálogo es al mismo tiempo el tema del diálogo mismo; eso que lo justifica es «aquello que nos habla», lo que «excede» la estructura enunciativa. Por otra parte, se pretenderá ensayar brevemente este diálogo centrándonos en un texto de Lacan y dos textos de Heidegger en los cuales el tema es ese exceso
“Das Ding”, el retorno y la estructura ontológica de la psicoaálisis. Una comprensión lacaniana de la filosofía de Heidegger.
Authors: Gracia Gómez Alfonso A.
Published: March 2021

El psicoanálisis y la filosofía mantienen una relación que debe leerse en el más complejo sentido de una ambivalencia originaria, que constitutivamente retorna. Da igual que se trate del eterno retorno de lo mismo, del retorno de lo reprimido o del retorno a Freud, porque en todos los casos se trata de poner en juego ese ejercicio enigmático, tan característico de la filosofía, que descubre sus objetos en el propio discurso, con ánimo a generarse un lugar que sirve como reflejo de un “otro” especular al que tiende con el mismo ahinco que lo repudia. Por ello, tanto el lenguaje de la filosofía como el del psicoanálisis están atravesados por una pregunta fundamental, y a menudo latente, que tiene que ver con la propia condición ingenua y tirana del sujeto.
Prepositioning and Local Purchasing for Emergency Operations Under Budget, Demand, and Supply Uncertainty
Authors: Eftekhar Mahyar , Jeannette Song Jing-Sheng , Webster Scott
Published: March 2021

Problem definition: Considering a mix of prepositioning and local purchasing, common to cover humanitarian demands in the aftermath of a rapid-onset disaster, we propose policies to determine preposition stock. These formulations are developed in the presence of demand, budget, and local supply uncertainties and for single-items delivery. Academic/practical relevance: The immediate period aftermath of a disaster is the most crucial period during which humanitarian organizations must supply relief items to beneficiaries. Yet, because of many unknowns such as time, place, and magnitude of a disaster, supply management is a significant challenge, and these decisions are made intuitively. The features and complexities we examine have not been studied in the literature. Methodology: We derive properties of the optimal solution, identify exact solution methods, and determine approximate methods that are easy to implement. Results: We (i) characterize the interplay of supply, demand, and budget uncertainties, as well as the impact of product characteristics on optimal prepo stock levels; (ii) show in what conditions the prepo stock is a simple newsvendor solution; and (iii) discuss the value of emergency funds. Managerial implications: We show that budget level is a key determinant of the optimal policy. When it is above a threshold, inventory increases in disaster frequency and severity, but the reverse is true otherwise. When budget is limited, the rate of savings from improved forecasts is amplified (attenuated) for critical (noncritical) items, reflecting opposing directional effects of mismatch cost and cost of insufficient funding. Our model can also be used to estimate the value of initiatives to mitigate constraints on local spend (e.g., a line of credit underwritten by large donors that is available during the immediate relief period).
right under our noses: the postponement of children's political equality and the NOW
Authors: Haynes Joanna , Murris Karin
Published: March 2021

Responding to the invitation of this special issue of Childhood and Philosophy this paper considers the ethos of facilitation in philosophical enquiry with children, and the spatial-temporal order of the community of enquiry. Within the Philosophy with Children movement, there are differences of thinking and practice on ‘facilitation’ in communities of philosophical enquiry, and we suggest that these have profound implications for the political agency of children. Facilitation can be enacted as a chronological practice of progress and development that works against child, in terms of political agency. This paper theorises practices of facilitation grounded in philosophies of childhood that assume listening to child/ren as equals, as already able to philosophise, and against sameness. We explore the political and ethical implications of the radical posthumanist reconfiguration of the ‘zipped’ body in the light of including the disciplinary, imaginative and enabling energies of chronological time through the concept now/ness.  We shift from ethics to ethos, and from ‘zipped’ to ‘unzipped’ bodies, through the notion of affect to explore the temporal and spatial dimensions of facilitation in Philosophy with Children and children’s political agency. We re-turn to David McKee’s Not Now Bernard (1980), getting ‘inside the text’, and attending to the postponement of equality in Philosophy with Children.
música, autismo e diferenças: a representação como violência em levinas e deleuze
Authors: Oliveira Stephan Malta , Damasceno Luísa Azevedo , Hofmann Nathalie Emmanuelle , Damasceno Letícia Azevedo , Schaefer Cecília Albuquerque reynaud , Da silveira Alba cristina Martins
Published: March 2021

The aim of this article is to investigate and discuss the notions of difference and representation in Emmanuel Levinas and Gilles Deleuze, articulating such notions through the example of a university extension project involving the formation of a musical ensemble composed of autistic children. Our research involved a review of four major philosophical works—Emmanuel Levinas’ Totality and Infinity; Among Us: Essays On Alterity; and “The Concept Of Difference In Bergson”; and Gilles Deleuze’s Difference and Repetition--in addition to secondary references. The main articulations of the investigation carried out in the project consist of aspects such as: taking responsibility for the autistic child through cultivating asymmetrical relationships, a process that takes place through sensibility, below any representation; and not totalizing the alterity involved while maintaining, at the same time, its radical difference. In addition, there is an emphasis in the work on the difference of each child, beyond his or her diagnostic identity, understanding that all participants are undergoing unique processes of differentiation, and that some differences are not more privileged than others, in that that such hierarchies are determined by power relations. Another contribution of this research is the emphasis on the intensive affective flows of children, and the construction of relationships of mutual affection, which increases the circulation of vital energy in each one. Finally, the results of the project are offered as guidelines for clinical practice, and for the cultivation of a politics of difference, as an alternative to hegemonic practices in autism studies in contemporary times.
Homeostase glicêmica e marcadores antropométricos associados à resistência insulínica em pacientes portadores de doença hepática gordurosa não alcoólica
Authors: Garcia e Silva Emerson Iago , Gudes Sarah Emanuely Macêdo , Cunha Bárbara Evelin de Souza , De Brito Camilla Araújo
Published: March 2021

Objetivo: Determinar medidas antropométricas preditivas associadas à resistência à insulina em pacientes portadores de doença hepática gordurosa não alcoólica. Métodos: Estudo transversal, quantitativo, realizado em dois centros ambulatoriais de Recife-PE. O público foi formado por indivíduos de ambos os sexos, acima de 18 anos, com diagnóstico de doença hepática gordurosa não alcoólica via ecografia abdominal. As variáveis antropométricas coletadas foram: circunferência da cintura, índice de massa corporal, índice de conicidade, razão cintura-quadril e cintura-estatura. A resistência à insulina foi determinada através do Homeostasis model assessment: insulin resistance (HOMA-IR). Para entender as diferenças entre as variáveis, o teste de U Mann-Whitney e testes de correlação foram realizados. Resultados: Participaram 75 indivíduos com predominância do sexo feminino (85%) e com idade superior a 60 anos (44%). A resistência à insulina foi elevada na população, perfazendo mais da metade dos indivíduos (73%). Com exceção do índice de massa corporal e da razão cintura-quadril, demais índices apresentaram associação estatisticamente significativa entre a presença da resistência à insulina com a esteatose hepática não alcoólica: razão cintura-estatura (p=0,004), índice de conicidade (p=0,031) e circunferência da cintura (p=0,001). No teste de correlação, apenas a circunferência da cintura (r =0,2184; p=0,05) e a razão cintura-quadril (r =0,2310; p=0,04) associaram-se. Conclusões: Os indicadores antropométricos são ferramentas aplicáveis na prática clínica e no contexto de doença hepática gordurosa não alcoólica; contudo, a circunferência da cintura e as razões cintura-estatura e cintura-quadril apresentaram as melhores predições.
Abordagem do Guia Alimentar para a População Brasileira em livros de ciências do ensino fundamental
Authors: Costa Gilcimara Bonifácia , Vincha Kellem Regina Rosendo , Carneiro Angélica Cotta Lobo Leite
Published: March 2021

Objetivo: Analisar a abordagem do conteúdo do Guia Alimentar para a População Brasileira em livros de ciências do ensino fundamental. Métodos: Realizou-se um estudo transversal descritivo. Foram analisados os 13 livros de ciências do 8º ano das coleções aprovadas pelo Ministério da Educação para serem usadas no triênio 2017 a 2019. Mediante a leitura dos capítulos que abordavam a alimentação e nutrição, foi identificada a presença de conteúdos relacionados à temática dos dez passos para uma alimentação adequada e saudável do Guia Alimentar, à menção ao Guia e à pirâmide alimentar. A partir dos conteúdos identificados, os dados foram submetidos à análise estatística descritiva e foram categorizados de acordo com os sentidos identificados na perspectiva da alimentação adequada e saudável. Resultados: Todas as temáticas foram identificadas nos livros, as relacionadas ao consumo de alimentos naturais, ultraprocessados e ingredientes culinários estiveram presentes em todos. O tema da comensalidade foi frequente, mas pontual, e os demais que podem estimular a adoção de uma alimentação adequada e saudável foram pouco explorados. Foram identificadas poucas menções ao Guia e ampla citação à pirâmide alimentar. Observou-se uma tendência dos livros de manter o enfoque biológico na abordagem da alimentação. Conclusões: Evidenciou-se a presença de conteúdos do Guia Alimentar nos livros de ciências, porém na abordagem predominou a perspectiva do racionalismo nutricional. Verificou-se a necessidade de revisão dos conteúdos para melhor difusão do conceito ampliado de alimentação e nutrição, o que pode viabilizar a inserção da Educação Alimentar e Nutricional no ambiente escolar.
Government funding for research into long COVID
Authors: Palmer Sarah Jane
Published: March 2021

Sarah Jane Palmer presents a quarterly overview of recently published guidance of relevance to cardiovascular nursing. This update covers the four studies selected to receive government funding for research into the definition, causes and treatment of long COVID.
Wound assessment and dressing selection: an overview
Authors: Bishop Alexandra
Published: March 2021

Wound healing consists of four overlapping phases. Holistic assessment of a wound is essential and can confirm whether healing is progressing as anticipated. Frameworks can assist the clinician to conduct the assessment in a systematic way and to plan appropriate care for the patient. Dressings form a relatively small part of the overall care plan, but with such an array available the choice can be overwhelming. This article provides an update on wound assessment using the TIMERS framework and considers the factors influencing dressing choice.
Clinical performance and quality of life impact of an absorbent bacteria-binding foam dressing
Authors: Seckam Abdul M , Twardowska-Saucha Krystyna , Heggemann Jan , Süß-Burghart Anja , Augustin Matthias
Published: March 2021

The aim of this prospective multicentre observational study was to assess the clinical performance and safety of Cutimed® Siltec® Sorbact® absorbent bacteria-binding foam dressing in wound healing and its impact on patients' quality of life (QoL). The study was conducted under routine clinical conditions in 5 study sites in Germany and Poland. Each patient with a venous leg ulcer (VLU) or a diabetic foot ulcer (DFU) was observed for 28 days (initial visit and close-out visit, as well as 3 control visits). An assessment of QoL of the patient was undertaken before and after the study. Sixty-two patients were included in the statistical analysis. Clinicians rated the following assessment parameters in relation to Cutimed Siltec Sorbact dressings as ‘very good’ to ‘good’: wearing comfort (rated by the patient), application and removal, exudate absorption with or without compression and fluid retention capacity with or without compression and infection management. The use of Cutimed Siltec Sorbact dressing was beneficial in absorbing wound exudate (chi-square=28.45, P value<0.001), reduction of the viscosity of wound exudate (chi-square=25.63, P value<0.001), and there were more intact, less macerated, red and oedematous wound surroundings. There was also a 9% decrease in the number of infected wounds at the close-out visit. Analysis of the Wound-QoL measures demonstrated a reduction in the perception of performance parameters associated with wound infection. It can therefore be deduced that the use of Cutimed Siltec Sorbact was effective in wound management and had positive implications for patients' QoL.
SARS-CoV-2 Variants and COVID-19: An Overview
Authors: Samaranayake Lakshman , Fakhruddin Kausar Sadia
Published: March 2021

All viruses, including coronaviruses, change over time. This leads to multiple progenies of viral strains, with virulence traits that are unlike those of their parents. This article provides an overview of how viral variants emerge, and the signs and symptoms of variant-related COVID-19.
Eating disorders on the rise in children
Authors: Forbes Lisa
Published: March 2021

The true impact of the Covid-19 pandemic on children is yet to be seen, but charities have warned of an increase in psychosocial issues, including eating disorders
Zoom lens with high zoom ratio design based on Gaussian bracket and particle swarm optimization
Authors: Fan Chengxiang , Yang Bo , Liu Yunpeng , Gu Pengxiang , Wang Xingqi , Zong Hui
Published: March 2021

In this paper, we use Gaussian brackets and a particle swarm optimization (PSO) algorithm to design a

20
×

four-group zoom lens with a focus tunable lens and two moving groups. This method uses Gaussian brackets to derive the paraxial design equations of the zoom lens and determine the lens parameters. In the optimization stage, we define an objective function as a performance indicator to optimize its first-order design and implement the PSO algorithm in MATLAB to find its global optimal first-order design. The optimized

20
×

zoom lens has a focal length of 4.5–90 mm and a total length of 145 mm. This method solves the difficulty of solving the initial structure of the zoom. Compared with traditional trial and error, the calculation speed is faster, the accuracy is higher, and it does not rely on the initial value. The results show that this method is suitable for the first-order design of complex optical systems.
Photo-assisted self-interference cancellation for in-band full-duplex radio-over-fiber system
Authors: Wang Jiaojiao , Yu Haiyang , Zhao Zeping , Zhang Zhike , Liu Jianguo
Published: March 2021

An optical approach to cancel the radio frequency self-interference for an in-band full-duplex radio-over-fiber system is proposed and experimentally demonstrated based on two Mach–Zehnder modulators and a balanced photodetector (BPD). The cancellation depth is larger than 50 dB and 24 dB for the single frequency and for a wideband signal, respectively. The application of the BPD eliminates the common mode noise and reduces no system flexibility because signal transmission is in one optical fiber by polarization multiplexing technology, instead of two fibers in the traditional self-interference cancellation system with a BPD. In addition, with no electrical delay and attenuation applied, the operational frequency band and cancellation depth are not confined by electronic devices.
Characterization and absolute calibration of an AERONET-OC radiometer
Authors: Johnson B. C. , Zibordi Giuseppe , Brown Steven W. , Feinholz Michael E. , Sorokin Mikhail G. , Slutsker Ilya , Woodward John T. , Yoon Howard W.
Published: March 2021

The Ocean Color component of the global Aerosol Robotic Network (AERONET-OC) utilizes CE-318 sun photometers modified for above-water radiometry from fixed structures such as oil rigs, lighthouses, and service platforms. Primarily, AERONET-OC measurements allow determination of the water-leaving radiance required for the validation of ocean color satellite data products. One instrument from the AERONET–OC network, identified as AERONET #080, was studied in this work. A laser-illuminated integrating sphere of known radiance enabled determination of the linearity with flux and absolute radiance responsivity at multiple wavelengths within seven of the AERONET #080 filter bands. We compared the results to calibrations from the AERONET facility at the Goddard Space Flight Center of the National Aeronautics and Space Administration and from the Joint Research Centre of the European Commission. These results agree within the estimated mean comparison uncertainty of 1.88 % (

k
=

2

). We also assessed these results using calibrated lamp-illuminated integrating spheres and observed a spectral dependence to the comparison results that is unexplained.
Chirality parameter sensing based on surface plasmon resonance D-type photonic crystal fiber sensors
Authors: Fan Bo , Zhang Tongmengxue , He Simin , Wang Maoyan , Li Hailong , Yu Mengxia , Li Guiping , Xu Jun
Published: March 2021

We report a method to sense a surrounding chiral drug based on D-type single-mode photonic crystal fiber (PCF) sensors in this paper. The electromagnetic theory of surface plasmon resonance on metal-chiral drug structure is derived. The wave equation containing constitutive relations of a chiral drug is given and integrated into the finite element method to compute the effective refractive index, confinement loss, and plasmon resonance wavelength for a D-type PCF sensor immersed in the chiral drug. The effects of the chirality parameter on resonance behaviors are displayed. The wavelength sensitivities of the chirality parameter for the sensor changing with different kinds of metal film layers, side-polished depth, and thickness of metal film layer are calculated. The wavelength sensitivity can reach a maximum of 17,580 nm/chirality as the refractive index and chirality parameter of the drug are 1.36 and 0.08, respectively. Furthermore, simultaneous dual-parameter detection of the chirality parameter and refractive index is realized by using two different D-type PCF sensors with gold and silver metal film layers, respectively. This study may provide sufficient guidelines to the field of biochemical sensing.
Characterization of a chromatic confocal displacement sensor integrated with an optical laser head
Authors: Zakrzewski A. , Jurewicz P. , Koruba P. , Ćwikła M. , Reiner J.
Published: March 2021

In this paper, the results of experimental characterization of an optical system consisting of a chromatic confocal displacement sensor integrated with an optical laser head are presented. As a result of integration, the part of the optical path of the displacement sensor was combined with the optical path of the laser beam. Consequently, a working distance of 250 mm for the optical system was achieved. The main aim of the characterization was to determine the calibration curve, as well as the application parameters of the system. The methodology for spectral data processing with particular emphasis on the effectiveness of various extraction algorithms is presented. The Lorentzian fitting was considered as the optimal algorithm for the optical system. Consequently, a large measuring range of 10 mm was obtained with perfect linear tendency of the calibration curve. The optical system was characterized by high accuracy equal to

±

0.11

%

of the measuring range, as well as 1 µm resolution. Moreover, the functionality of the system was verified on materials commonly used in laser processing and additive manufacturing. Finally, the system was validated through a comparative measurement with a laser profiler.
Theory of light reflection and transmission by a plasmonic nanocomposite slab: emergence of broadband perfect absorption
Authors: Bordo V. G.
Published: March 2021

A theory of light reflection and transmission by an optically thin
nanocomposite slab that contains randomly distributed metal
nanoparticles (NPs) is developed. The underlying model treats NPs as
point dipoles and employs a dyadic Green’s function known analytically
for a slab that allows one to obtain the refection and transmission
coefficients in a fully analytical form. The model also takes into
account the enhanced decay of localized surface plasmons in dense NP
arrays and light scattering at the slab surface roughness. It is
demonstrated that the first effect leads to broadband perfect
absorption observed in such nanocomposites, whereas the second one is
responsible for its omnidirectional character and polarization
insensitivity. These findings open up new possibilities to engineer
broadband perfect absorption in plasmonic nanocomposites.
Characterization of suspended membrane waveguides towards a photonic atom trap integrated platform
Authors: Gehl Michael , Kindel William , Karl Nicholas , Orozco Adrian , Musick Katherine , Trotter Douglas , Dallo Christina , Starbuck Andrew , Leenheer Andrew , DeRose Christopher , Biedermann Grant , Jau Yuan-Yu , Lee Jongmin
Published: March 2021

We demonstrate an optical waveguide device, capable of supporting the high, in-vacuum, optical power necessary for trapping a single atom or a cold atom ensemble with evanescent fields. Our photonic integrated platform, with suspended membrane waveguides, successfully manages optical powers of 6 mW (500 μm span) to nearly 30 mW (125 μm span) over an un-tethered waveguide span. This platform is compatible with laser cooling and magneto-optical traps (MOTs) in the vicinity of the suspended waveguide, called the membrane MOT and the needle MOT, a key ingredient for efficient trap loading. We evaluate two novel designs that explore critical thermal management features that enable this large power handling. This work represents a significant step toward an integrated platform for coupling neutral atom quantum systems to photonic and electronic integrated circuits on silicon.
Self-assembled microcage fabrication for manipulating and selectively capturing microparticles and cells
Authors: Li Peiwen , Yu Haibo , Wang Xiaoduo , Wen Yangdong , Zhao Wenxiu , Luo Hao , Ge Zhixing , Liu Lianqing
Published: March 2021

Single-cell-scale selective manipulation and targeted capture play a vital role in cell behavior analysis. However, selective microcapture has primarily been performed in specific circumstances to maintain the trapping state, making the subsequent in situ characterization and analysis of specific particles or cells difficult and imprecise. Herein, we propose a novel method that combines femtosecond laser two-photon polymerization (TPP) micromachining technology with the operation of optical tweezers (OTs) to achieve selective and targeted capture of single particles and cells. Diverse ordered microcages with different shapes and dimensions were self-assembled by micropillars fabricated via TPP. The micropillars with high aspect ratios were processed by single exposure, and the parameters of the micropillar arrays were investigated to optimize the capillary-force-driven self-assembly process of the anisotropic microcages. Finally, single microparticles and cells were selectively transported to the desired microcages by manipulating the flexibly of the OTs in a few minutes. The captured microparticles and cells were kept trapped without additional forces.
Impact of nonlinearity including bleaching in MUTC photodetectors on RF-modulated electro-optic frequency combs
Authors: Jamali Mahabadi Seyed Ehsan , Carruthers Thomas F. , Menyuk Curtis R. , McKinney Jason D. , Williams Keith J.
Published: March 2021

We use the drift-diffusion equations to calculate the responsivity of a modified uni-traveling carrier (MUTC) photodetector (PD) with a frequency comb input that is generated by a series of short optical pulses. We first use experimental results for the responsivity of the MUTC PD to obtain an empirical model of bleaching in pulsed mode. We incorporate our empirical bleaching model into a drift-diffusion model to calculate the impact of nonlinearity in an MUTC PD on RF-modulated electro-optic frequency combs. We quantify the nonlinearity using the second- and third-order intermodulation distortion powers (IMD2 and IMD3), from which we calculate the second- and third-order output intercept points (OIP2 and OIP3). In contrast to a continuous wave (CW) input for which there is a single IMD2 and IMD3 and hence a single OIP2 and OIP3, each comb line n has its own IMD2
n
, IMD3
n
, OIP2
n
, and OIP3
n
associated with it. We determine the IMD2
n
, IMD3
n
, OIP2
n
, and OIP3
n
, and we compare the results with and without bleaching. We find that the impact of bleaching is complex and, somewhat surprisingly, not always detrimental. The principal effect of bleaching is to lower the responsivity, which decreases the nonlinearity due to space charge. While bleaching always reduces the OIP2
n
and OIP3
n
, we find that bleaching leads to a decreased distortion-to-signal ratio for large n.
Low-loss c-axis oriented Zn0.72Mg0.28O nonlinear planar optical waveguides on silicon
Authors: Meng Lei , Chai Hongyu , Lv Zunren , Yang Tao
Published: March 2021

A material platform of highly c-axis oriented Zn1-xMgxO thin films is developed for nonlinear planar waveguides and electro-optic modulators on Si. Mg content in the film greatly influences the quality of film growth. The second harmonic generation measurement and Maker-fringe analysis reveal that the second-order nonlinear susceptibility tensor element χ33 of the annealed Zn0.72Mg0.28O is approximately 4.2 times larger than that of ZnO. The propagation loss of 633 nm wavelength light in the annealed air/Zn0.72Mg0.28O/SiO2 slab waveguide is 0.68 ± 0.09 dB/cm and 0.48 ± 0.03 dB/cm for the TE0 and TM0 modes, respectively. These results suggest the great potential of the c-axis oriented Zn0.72Mg0.28O nonlinear planar waveguides for applications in on-chip optical interconnects.
On the performance of a tunable grating-based high sensitivity unidirectional plasmonic sensor
Authors: González-Colsa Javier , Serrera Guillermo , Saiz José M. , González Francisco , Moreno Fernando , Albella Pablo
Published: March 2021

Optical biosensing is currently an intensively active research area, with an increasing demand of highly selective, sensitivity-enhanced and low-cost devices where different plasmonic approaches have been developed. In this work we propose a tunable optimized grating-based gold metasurface that can act both as a high sensitivity sensor device (up to 1500 nm/RIU) and as an unidirectional plasmon source. The theory behind surface plasmon polariton generation is recalled to thoroughly understand the influence that every parameter of the grating source has on the performance of the proposed device. The results and conclusions discussed here offer a key step toward the design of biosensors based on excitation of surface plasmons polaritons by grating-based structures or in the process of creating new nanophotonic circuit devices.
Coherent atomic mirror formed by randomly distributed ions inside a crystal
Authors: Nandi Arindam , An Haechan , Hosseini Mahdi
Published: March 2021

Spatial distribution of atoms plays an important role in the interaction of atomic ensembles and electromagnetic fields. In this Letter, we show that by spatio-spectral tailoring of atomic absorption, one can effectively carve out a periodic array from randomly distributed atomic ensembles hosted by a solid-state crystal. Furthermore, we observe collective atomic resonances and coherent backscattering of light from rare-earth-doped crystals. Coherent backscattering as high as 20% was observed for light at telecom wavelength from Er ions, forming an effective array with over 5000 centers.
High-resolution Fourier light-field microscopy for volumetric multi-color live-cell imaging
Authors: Hua Xuanwen , Liu Wenhao , Jia Shu
Published: March 2021

Volumetric interrogation of the organization and processes of intracellular organelles and molecules in cellular systems with a high spatiotemporal resolution is essential for understanding cell physiology, development, and pathology. Here, we report high-resolution Fourier light-field microscopy (HR-FLFM) for fast and volumetric live-cell imaging. HR-FLFM transforms conventional cell microscopy and enables exploration of less accessible spatiotemporal-limiting regimes for single-cell studies. The results present a near-diffraction-limited resolution in all three dimensions, a five-fold extended focal depth to several micrometers, and a scanning-free volume acquisition time up to milliseconds. The system demonstrates instrumentation accessibility, low photo damage for continuous observation, and high compatibility with general cell assays. We anticipate HR-FLFM to offer a promising methodological pathway for investigating a wide range of intracellular processes and functions with exquisite spatiotemporal contextual details.
Repulsive expansion dynamics in colony growth and gene expression
Authors: Cao Yangxiaolu , Neu John , Blanchard Andrew E. , Lu Ting , You Lingchong
Published: March 2021

Spatial expansion of a population of cells can arise from growth of microorganisms, plant cells, and mammalian cells. It underlies normal or dysfunctional tissue development, and it can be exploited as the foundation for programming spatial patterns. This expansion is often driven by continuous growth and division of cells within a colony, which in turn pushes the peripheral cells outward. This process generates a repulsion velocity field at each location within the colony. Here we show that this process can be approximated as coarse-grained repulsive-expansion kinetics. This framework enables accurate and efficient simulation of growth and gene expression dynamics in radially symmetric colonies with homogenous z-directional distribution. It is robust even if cells are not spherical and vary in size. The simplicity of the resulting mathematical framework also greatly facilitates generation of mechanistic insights.
Natural variation in the regulation of neurodevelopmental genes modifies flight performance in Drosophila
Authors: Spierer Adam N. , Mossman Jim A. , Smith Samuel Pattillo , Crawford Lorin , Ramachandran Sohini , Rand David M.
Published: March 2021

The winged insects of the orderDipteraare colloquially named for their most recognizable phenotype: flight. These insects rely on flight for a number of important life history traits, such as dispersal, foraging, and courtship. Despite the importance of flight, relatively little is known about the genetic architecture of flight performance. Accordingly, we sought to uncover the genetic modifiers of flight using a measure of flies’ reaction and response to an abrupt drop in a vertical flight column. We conducted a genome wide association study (GWAS) using 197 of theDrosophilaGenetic Reference Panel (DGRP) lines, and identified a combination of additive and marginal variants, epistatic interactions, whole genes, and enrichment across interaction networks.Egfr, a highly pleiotropic developmental gene, was among the most significant additive variants identified. We functionally validated 13 of the additive candidate genes’ (Adgf-A/Adgf-A2/CG32181,bru1,CadN,flapper(CG11073),CG15236,flippy(CG9766),CREG,Dscam4,form3,fry,Lasp/CG9692,Pde6,Snoo), and introduce a novel approach to whole gene significance screens:PEGASUS_flies. Additionally, we identifiedppk23, an Acid Sensing Ion Channel (ASIC) homolog, as an important hub for epistatic interactions. We propose a model that suggests genetic modifiers of wing and muscle morphology, nervous system development and function, BMP signaling, sexually dimorphic neural wiring, and gene regulation are all important for the observed differences flight performance in a natural population. Additionally, these results represent a snapshot of the genetic modifiers affecting drop-response flight performance inDrosophila, with implications for other insects.
Effects of rainfall intensity on runoff and nutrient loss of gently sloping farmland in a karst area of SW China
Authors: Yao Yiwen , Dai Quanhou , Gao Ruxue , Gan Yixian , Yi Xingsong
Published: March 2021

Nutrient losses from sloping farmland in karst areas lead to the decline in land productivity and nonpoint source pollution. A specially tailored steel channel with an adjustable slope and underground hole fissures was used to simulate the microenvironment of the "dual structure" of the surface and underground of sloping farmland in a karst area. The artificial rainfall simulation method was used to explore the surface and underground runoff characteristics and nutrient losses from sloping farmland under different rainfall intensities. The effect of rainfall intensity on the nutrient loss of farmland on karst sloping land was clarified. The results showed that the surface was the main route of runoff and nutrient loss during the rainy season on sloping farmland in karst areas. The influence of rainfall intensity on the nutrients in surface runoff was more substantial than that on underground runoff nutrients. Nutrient loss was more likely to occur underground than on the surface. The losses of total nitrogen, total phosphorus, and total potassium in surface and underground runoff initially increased and then gradually stabilized with the extension of rainfall duration and increased with increasing rainfall intensity and the amount of nutrient runoff. The output of nutrients through surface runoff accounted for a high proportion of the total, and underground runoff was responsible for a low proportion. Although the amount of nutrients output by underground runoff was small, it could directly cause groundwater pollution. The research results provide a theoretical reference for controlling land source pollution from sloping farming in karst areas.
A qualitative study of clinicians’ perspectives on independent rights advice for involuntary psychiatric patients in British Columbia, Canada
Authors: Cheung Iva W. , Silva Diego S. , Miller Kimberly J. , Michalak Erin E. , Goldsmith Charles H.
Published: March 2021

Background

In British Columbia (BC), Canada, clinicians are responsible for giving involuntary psychiatric patients rights information upon admission. Yet an investigation by the BC Office of the Ombudsperson found that clinicians are not always fulfilling this responsibility. The Ombudsperson recommended that the provincial government fund an independent body to give rights advice to patients.

Methods

To understand how clinicians feel about this recommendation, focus groups of clinicians who may give psychiatric patients rights information (n = 81) were conducted in Vancouver, BC, to probe their attitudes toward independent rights advisors. The focus group transcripts were thematically analyzed.

Results

Most clinicians believe that giving rights information is within their scope of practice, although some acknowledge that it poses a conflict of interest when the patient wishes to challenge the treatment team’s decisions. Participants’ chief concerns about an independent rights-advice service were that (a) patients may experience a delay in receiving their rights information, (b) integrating rights advisors into the workflow would complicate an already chaotic admission process, and (c) more patients would be counselled to challenge their hospitalization, leading to an increased administrative workload for clinical staff. However, many participants believed that independent rights advisors would be a positive addition to the admission process, both allowing clinicians to focus on treatment and serving as a source of rights-related information.

Conclusions

Participants were generally amenable to an independent rights-advice service, suggesting that the introduction of rights advisors need not result in an adversarial relationship between treatment team and patient, as opponents of the proposal fear. Clearly distinguishing between basic rights information and in-depth rights advice could address several of the clinicians’ concerns about the role that independent rights advisors would play in the involuntary admission process. Clinicians’ and other stakeholders’ concerns should be considered as the province develops its rights-advice service.