bluuebunny/crossref_metadata_2025 huggingface dataset:
Mutation of PFN1 Gene in an Early Onset, Polyostotic Paget-like Disease
Authors: Merlotti Daniela , Materozzi Maria , Bianciardi Simone , Guarnieri Vito , Rendina Domenico , Volterrani Luca , Bellan Cristiana , Mingiano Christian , Picchioni Tommaso , Frosali Alessandro , Orfanelli Ugo , Cenci Simone , Gennari Luigi
Published: May 2020

Context

Paget disease of bone (PDB) is a metabolic bone disease whose genetic cause remains unknown in up to 50% of familial patients.

Objective

Our aim was to investigate the underlying genetic defect in a large pedigree with a severe, early onset, autosomal dominant form of PDB across 3 generations.

Methods

Whole exome sequencing was performed in affected and unaffected family members, and then mutation screening was replicated in a sample of PDB patients with early-onset, polyostotic PDB.

Results

We identified a frameshift D107Rfs*3 mutation in PFN1 (encoding for profilin 1, a highly conserved regulator of actin-polymerization and cell motility) causing the truncation of the C-terminal part of the protein. The mutation was also detected in a 17-year-old asymptomatic family member who upon biochemical and radiological analyses was indeed found to be affected. Sequencing of the entire PFN1 coding region in unrelated PDB patients identified the same mutation in 1 patient. All mutation carriers had a reduced response to bisphosphonates, requiring multiple zoledronate infusions to control bone pain and achieve biochemical remission over a long term. In vitro osteoclastogenesis in peripheral blood mononuclear cells (PBMCs) from mutation carriers showed a higher number of osteoclasts with PDB-like features. A similar phenotype was observed upon PFN1 silencing in murine bone marrow-derived monocytes, suggesting that the frameshift PFN1 mutation confers a loss of function in profilin 1 activity that induces PDB-like features in the osteoclasts, likely due to enhanced cell motility and actin ring formation.

Conclusions

Our findings indicate that PFN1 mutation causes an early onset, polyostotic PDB-like disorder.
Residual Corticosteroid Production in Autoimmune Addison Disease
Authors: Sævik Åse Bjorvatn , Åkerman Anna-Karin , Methlie Paal , Quinkler Marcus , Jørgensen Anders Palmstrøm , Höybye Charlotte , Debowska Aleksandra J , Nedrebø Bjørn Gunnar , Dahle Anne Lise , Carlsen Siri , Tomkowicz Aneta , Sollid Stina Therese , Nermoen Ingrid , Grønning Kaja , Dahlqvist Per , Grimnes Guri , Skov Jakob , Finnes Trine , Valland Susanna F , Wahlberg Jeanette , Holte Synnøve Emblem , Simunkova Katerina , Kämpe Olle , Husebye Eystein Sverre , Bensing Sophie , øksnes Marianne
Published: May 2020

Context

Contrary to current dogma, growing evidence suggests that some patients with autoimmune Addison disease (AAD) produce corticosteroids even years after diagnosis.

Objective

To determine frequencies and clinical features of residual corticosteroid production in patients with AAD.

Design

Two-staged, cross-sectional clinical study in 17 centers (Norway, Sweden, and Germany). Residual glucocorticoid (GC) production was defined as quantifiable serum cortisol and 11-deoxycortisol and residual mineralocorticoid (MC) production as quantifiable serum aldosterone and corticosterone after > 18 hours of medication fasting. Corticosteroids were analyzed by liquid chromatography–tandem mass spectrometry. Clinical variables included frequency of adrenal crises and quality of life. Peak cortisol response was evaluated by a standard 250 µg cosyntropin test.

Results

Fifty-eight (30.2%) of 192 patients had residual GC production, more common in men (n = 33; P < 0.002) and in shorter disease duration (median 6 [0-44] vs 13 [0-53] years; P < 0.001). Residual MC production was found in 26 (13.5%) patients and associated with shorter disease duration (median 5.5 [0.5-26.0] vs 13 [0-53] years; P < 0.004), lower fludrocortisone replacement dosage (median 0.075 [0.050-0.120] vs 0.100 [0.028-0.300] mg; P < 0.005), and higher plasma renin concentration (median 179 [22-915] vs 47.5 [0.6-658.0] mU/L; P < 0.001). There was no significant association between residual production and frequency of adrenal crises or quality of life. None had a normal cosyntropin response, but peak cortisol strongly correlated with unstimulated cortisol (r = 0.989; P < 0.001) and plasma adrenocorticotropic hormone (ACTH; r = –0.487; P < 0.001).

Conclusion

In established AAD, one-third of the patients still produce GCs even decades after diagnosis. Residual production is more common in men and in patients with shorter disease duration but is not associated with adrenal crises or quality of life.
Transcriptional Control of Circadian Rhythms and Metabolism: A Matter of Time and Space
Authors: Kim Yong Hoon , Lazar Mitchell A
Published: May 2020

All biological processes, living organisms, and ecosystems have evolved with the Sun that confers a 24-hour periodicity to life on Earth. Circadian rhythms arose from evolutionary needs to maximize daily organismal fitness by enabling organisms to mount anticipatory and adaptive responses to recurrent light-dark cycles and associated environmental changes. The clock is a conserved feature in nearly all forms of life, ranging from prokaryotes to virtually every cell of multicellular eukaryotes. The mammalian clock comprises transcription factors interlocked in negative feedback loops, which generate circadian expression of genes that coordinate rhythmic physiology. In this review, we highlight previous and recent studies that have advanced our understanding of the transcriptional architecture of the mammalian clock, with a specific focus on epigenetic mechanisms, transcriptomics, and 3-dimensional chromatin architecture. In addition, we discuss reciprocal ways in which the clock and metabolism regulate each other to generate metabolic rhythms. We also highlight implications of circadian biology in human health, ranging from genetic and environment disruptions of the clock to novel therapeutic opportunities for circadian medicine. Finally, we explore remaining fundamental questions and future challenges to advancing the field forward.
High-Flow Nasal Cannula Oxygen in Patients Having Anesthesia for Advanced Esophagogastroduodenoscopy: HIFLOW-ENDO, a Randomized Clinical Trial
Authors: Mazzeffi Michael A. , Petrick Kendra M. , Magder Laurence , Greenwald Bruce D. , Darwin Peter , Goldberg Eric M. , Bigeleisen Paul , Chow Jonathan H. , Anders Megan , Boyd Cynthia M. , Kaplowitz Jeremy S. , Sun Kai , Terrin Michael , Rock Peter
Published: May 2020

BACKGROUND:

Over 6 million esophagogastroduodenoscopy (EGD) procedures are performed in the United States each year. Patients having anesthesia for advanced EGD procedures, such as interventional procedures, are at high risk for hypoxemia.

METHODS:

Our primary study aim was to evaluate whether high-flow nasal cannula (HFNC) oxygen reduces the incidence of hypoxemia during anesthesia for advanced EGD. Secondarily, we studied whether HFNC oxygen reduces hypercarbia or hypotension. After obtaining written informed consent, adults having anesthesia for advanced EGD, expected to last longer than 15 minutes, were randomly assigned to receive HFNC oxygen or standard nasal cannula (SNC) oxygen. The primary outcome was occurrence of one or more hypoxemia events during anesthesia, defined by arterial oxygen saturation <92% for at least 15 consecutive seconds. Secondary outcomes were occurrence of one or more hypercarbia or hypotension events. A hypercarbia event was defined by a transcutaneous CO2 measurement 20 mm Hg or more above baseline, and a hypotension event was defined by a mean arterial blood pressure measurement 25% or more below baseline.

RESULTS:

Two hundred seventy-one adult patients were enrolled and randomized, and 262 patients completed study procedures. Eight randomized patients did not complete study procedures due to changes in their anesthesia or endoscopy plan. One patient was excluded from analysis because their procedure was aborted after 1 minute. Patients who received HFNC oxygen (N = 132) had a significantly lower incidence of hypoxemia than those who received SNC oxygen (N = 130; 21.2% vs 33.1%; hazard ratio [HR] = 0.59 [95% confidence interval {CI}, 0.36–0.95]; P = .03). There was no difference in the incidence of hypercarbia or hypotension between the groups. The HR for hypercarbia with HFNC oxygen was 1.29 (95% CI, 0.89–1.88; P = .17), and the HR for hypotension was 1.25 (95% CI, 0.86–1.82; P = .25).

CONCLUSIONS:

HFNC oxygen reduces the incidence of hypoxemia during anesthesia for advanced EGD and may offer an opportunity to enhance patient safety during these procedures.
Of Human Flesh
Authors: Moten Fred
Published: May 2020

This is an excerpt from an interview of R.A. Judy conducted by Fred Moten in Pittsburgh, Pennsylvania, over the course of two days, May 26–27, 2017. The remaining sections appear at http://www.boundary2.org/moten-judy-interview/.
Transient and lineage-restricted requirement of Ebf3 for sternum ossification
Authors: Kuriki Mao , Sato Fuminori , Arai Hiroyuki N. , Sogabe Maina , Kaneko Mari , Kiyonari Hiroshi , Kawakami Koichi , Yoshimoto Yuki , Shukunami Chisa , Sehara-Fujisawa Atsuko
Published: May 2020

Osteoblasts arise from bone-surrounding connective tissue containing tenocytes and fibroblasts. Lineages of these cell populations and mechanisms of their differentiation are not well understood. Screening enhancer-trap lines of zebrafish allowed us to identify Ebf3 as a transcription factor marking tenocytes and connective tissue cells in skeletal muscle of embryos. Knockout of Ebf3 in mice had no effect on chondrogenesis but led to sternum ossification defects as a result of defective generation of Runx2+ pre-osteoblasts. Conditional and temporal Ebf3 knockout mice revealed requirements of Ebf3 in the lateral plate mesenchyme cells (LPMs), especially in tendon/muscle connective tissue cells, and a stage-specific Ebf3 requirement at embryonic day 9.5-10.5. Upregulated expression of connective tissue markers, such as Egr1/2 and Osr1, increased number of Islet1+ mesenchyme cells, and downregulation of gene expression of the Runx2 regulator Shox2 in Ebf3-deleted thoracic LPMs suggest crucial roles of Ebf3 in the onset of lateral plate mesoderm differentiation towards osteoblasts forming sternum tissues.
The sonar beam of Macrophyllum macrophyllum implies ecological adaptation under phylogenetic constraint
Authors: Olsen Mads Nedergaard , Surlykke Annemarie , Jakobsen Lasse
Published: May 2020

All animals are adapted to their ecology within the bounds of their evolutionary heritage. Echolocating bats clearly show such adaptations and boundaries through their biosonar call design. Adaptations include not only the overall time-frequency structure, but also the shape of the emitted echolocation beam. Macrophyllum macrophyllum is unique within the phyllostomid family, being the only species to predominantly hunt for insects in the open, on or above water and as such it presents an interesting case for comparing the impact of phylogeny and ecology as it originates from a family of low-intensity, high-directionality gleaning bats, but occupies a niche dominated by very loud and substantially less directional bats. Here we examined the sonar beam pattern of M. macrophyllum in the field and in a flight room and compared it to closely related species with very different feeding ecology and to that of the niche sharing but distantly related Myotis daubentonii. Our results show that M. macrophyllum uses higher source-levels and emits less directional calls than other phyllostomids. In the field its call directionality is comparable to M. daubentonii, but in the flight room M. macrophyllum is substantially more directional. Hence our results indicate that ecology influences the emitted call, pushing the bats to emit a louder and broader beam than other phyllostomids, but that phylogeny, does limit the emitted intensity and flexibility of the overall beam pattern.
Detecting level of wetland encroachment for urban agriculture in Uganda using hyper-temporal remote sensing
Authors: Kabiri Stella , Allen Molly , Okuonzia Juduth Toma , Akello Beatrice , Ssabaganzi Rebecca , Mubiru Drake
Published: May 2020

Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation. In Uganda, wetlands cover an area of 11% of the country’s land area, of which half have been converted to industry and residential areas, and urban agriculture. Here, we investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in a period of 30 years. Secondly, we demonstrate a simple methodology to monitor agriculture on encroached wetlands.

Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment from 1986 to 2016. Using MODIS NDVI 16-day composites at 500-meter spatial resolution, we generated distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm.

Results: Over 30 years, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost. Agriculture areas have doubled, of which 16,488 ha (23%) were reclaimed from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. Major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%).

Conclusions: The Kampala-Wakiso wetlands have been disappearing at a rate of 2500 ha annually for the last 30 years. At this rate, there will be no wetlands left by 2029. Policy recommendations should promote wetland reclamation programs so as to restore and reconstruct lost and fragmented wetlands; should mandate food security and poverty eradication to convene with ministries regulating wetlands to merge conflicting policies; and should develop polices that are inclusive of challenges faced by the urban poor while at the same time minimize the pressures on urban environments.
Apolipoprotein E expression pattern in human induced pluripotent stem cells during in vitro neural induction
Authors: Lee Hyunah , Nowosiad Paulina , Dutan Polit Lucia M. , Price Jack , Srivastava Deepak P. , Thuret Sandrine
Published: May 2020

Apolipoprotein E (APOE) is a multifunctional protein that plays significant roles in important cellular mechanisms in peripheral tissues and is as well expressed in the central nervous system, notably by adult neural stem cells (NSCs) in the hippocampus. Evidence from animal studies suggest that APOE is critical for adult NSC maintenance. However, whether APOE has the potential to play a similar role in human NSCs has not been directly investigated. To address this question, we conducted a focused study characterising APOE gene and protein expression in an in vitro model of neural differentiation utilising human induced pluripotent stem cells. We found that APOE gene expression was dramatically decreased as the cells became more differentiated, indicating that APOE expression levels reflect the degree of cellular differentiation during neural induction. Furthermore, qualitative analysis results of immunocytochemistry showed that intracellular localisation of APOE protein becomes more pronounced as neural differentiation progresses. Taken together, our findings suggest a potential role for APOE in human NSC maintenance and justify further investigations being carried out to understand whether changes in APOE levels can directly impact the neurogenic capacity of human stem cells.
Prior-Independent Optimal Auctions
Authors: Allouah Amine , Besbes Omar
Published: May 2020

Auctions are widely used in practice. Although auctions are also extensively studied in the literature, most of the developments rely on the significant common prior assumption. We study the design of optimal prior-independent selling mechanisms: buyers do not have any information about their competitors, and the seller does not know the distribution of values but only knows a general class to which it belongs. Anchored on the canonical model of buyers with independent and identically distributed values, we analyze a competitive ratio objective in which the seller attempts to optimize the worst-case fraction of revenues garnered compared with those of an oracle with knowledge of the distribution. We characterize properties of optimal mechanisms and in turn establish fundamental impossibility results through upper bounds on the maximin ratio. By also deriving lower bounds on the maximin ratio, we are able to crisply characterize the optimal performance for a spectrum of families of distributions. In particular, our results imply that a second price auction is an optimal mechanism when the seller only knows that the distribution of buyers has a monotone nondecreasing hazard rate, and it guarantees at least 71.53% of oracle revenues against any distribution within this class. Furthermore, a second price auction is near optimal when the class of admissible distributions is that of those with nondecreasing virtual value function (a.k.a. regular). Under this class, it guarantees a fraction of 50% of oracle revenues, and no mechanism can guarantee more than 55.6%.

This paper was accepted by Kalyan Talluri, revenue management and market analytics.
Review: Application of Infrared Thermography in Livestock Monitoring
Authors: Zhang Changzhen , Xiao Deqin , Yang Qiumei , Wen Zhifen , Lv Lishan
Published: May 2020

Highlights

As a non-invasive temperature detection technology, IRT can provide dynamic information on skin temperature changes caused by physiological processes of livestock.

IRT will become a more valuable detection tool for evaluating various signs and behavior changes of livestock.

With the continuous development of information technology, it is necessary to use IRT to explore more expected and innovative information.

Abstract. Infrared thermography (IRT) is a non-invasive temperature detection technology characterized by non-destructive, long-distance measurement and high sensitivity. IRT measures mid-wave to long-wave infrared radiation emanating from objects and converts this radiation into visual images or videos of the temperature distribution and temperature changes. Because temperature is an important environmental parameter that affects livestock physiology and metabolic heat production, measurement of animal temperature and energy exchange in field environments is a useful tool for understanding physiological changes in animals. Traditional measurement methods of animal temperature are extremely time-consuming and labor-intensive. As a non-contact method, IRT provides a new method for physiological data acquisition. However, IRT is also subject to a number of uncertainties, thus requiring optimal modeling using built-in software. Therefore, this study reviews applications of IRT in livestock production, including reproduction, growth, and diseases, and discusses some of the better-known approaches and the latest research findings for IRT in livestock production. Keywords: Diseases, Growth, Infrared thermography, Reproduction.
Application of WeChat Mini-Program and Wi-Fi SoC in Agricultural IoT: A Low-Cost Greenhouse Monitoring System
Authors: Zhou Lei , Qiu Zhengjun , He Yong
Published: May 2020

Highlights

A quick solution for developing and deploying custom agricultural IoT systems is proposed.

Low-cost and high-performance devices are used for the design of sensor nodes.

A mobile application based on WeChat Mini-Program is developed for device and data management.

The proposed system brings convenience to both users and developers.

Abstract. Increasing demand for automatic management of agricultural production and real-time remote monitoring has increased the need for smart devices, wireless technologies, and sensors. The internet of things (IoT) has emerged as a common technology for the management of multiple devices by multiple users. Some professional solutions are relatively difficult to implement for researchers who are interested in agricultural IoT but do not have requisite skills in computers and electronics. The unfriendliness of the user software limits the practical application of agricultural IoT in China. This article presents a simple solution based on an SoC (system-on-chip) and WeChat mini-program that focuses on low-cost hardware, rapid development, user-friendly application design, and helping developers get a quick start in building a DIY monitoring system. The ESP8266, a high-performance SoC, is used as the microcontroller and Wi-Fi module to transfer the sensor data to a remote server. A WeChat mini-program provides the graphical user interface, enabling users to manage devices and access data by clicking. Users can log into the system using their WeChat accounts and bind devices by scanning QR codes on the devices. Thus, the complex management and device binding in conventional systems can be overcome. The system is easy to be expand and has great potential for greenhouse environmental monitoring in China. Keywords: Greenhouse ambient monitoring, Internet of things, WeChat mini-program, Wi-Fi SoC.
Comparative Evaluation of Poultry-Human and Poultry-Robot Avoidance Distances
Authors: Parajuli Pratik , Huang Yanbo , Tabler Tom , Purswell Joseph L. , DuBien Janice L. , Zhao Yang
Published: May 2020

Highlights

Compared to a human, a robot operated properly would not induce more fear in broilers.

Bird age, robot operating speed, and operation frequency may affect poultry-robot avoidance distances.

Broiler and hen avoidance distances decrease as the birds become older.

Higher robot operating speeds increase poultry-robot ADs for broilers and white hens, but not for brown hens

Abstract. Advances in robotics promote interest in applications in the poultry industry to reduce human labor; however, skeptics express concerns regarding potential animal stress stemming from poultry-robot interactions. The objective of this study was to evaluate the avoidance distance (AD), a parameter reflecting stress in an animal due to an approaching object, of broilers and laying hens to a human assessor and a robotic ground vehicle. ADs were determined for birds at different ages (2, 4, 6, and 8 week old broilers; 28, 47, and 66 week old brown hens; and 27, 46, and 70 week old white hens) in a commercial broiler house and two commercial cage-free hen houses. The poultry-robot ADs were determined at three robot operating speeds (0.2, 0.4, and 0.6 m s-1) and two operation frequencies (bi-weekly and daily, for broilers only). The results show that the overall poultry-human and poultry-robot ADs were, respectively, 48 to 82 cm and 83 to 110 cm for broilers, 54 to 87 cm and 114 to 131 cm for brown hens, and 71 to 76 cm and 92 to 99 cm for white hens when the birds experienced the robot on test days only. Broiler-robot ADs significantly decreased to 30 to 63 cm when the birds were exposed to the robot daily, reflecting less stress induced by the robot than by the human. Poultry ADs to the human and robot tended to decrease for older birds. Slower robot operating speeds led to shorter ADs for broilers at 6 and 8 weeks of age and for white hens at all ages but did not affect ADs for broilers at 2 and 4 weeks of age and brown hens at all ages. Slower robot operating speeds also reduced the bird fleeing speed (FS). It is concluded that the robot did not induce more stress than the human in the broilers. The baseline poultry-robot ADs obtained in this study provide valuable information for understanding poultry interactions with robots and may help optimize robot operations for application in the poultry industry. Keywords: Animal welfare, Avoidance distance (AD), Broiler, Laying hens, Robotics.
Dust Content and Adhesion Characteristics of Five Corn Samples
Authors: Plumier Benjamin M. , Zhao Yumeng , Casada Mark E. , Maghirang Ronaldo G. , Ambrose R. P. Kingsly
Published: May 2020

Highlights

The corn sample and centrifuge speed interactions were statistically significant predictors of dust generation.

Attachment strengths of dust particles were calculated, with forces ranging from less than 4.6 × 10-10 N to 2.1 × 10-8 N.

A sequential centrifuge experiment indicated a bimodal distribution of adhesion forces.

Abstract. Grain dust explosions are a constant threat to the grain handling industry. Explosions occur when dust accumulates beyond the minimum explosion concentration in a confined area and is exposed to an ignition source. Handling and grain unloading conditions that generate dust, the minimum explosive dust concentration, overpressure from an explosion, and other factors that lead to grain dust explosion are well documented in the literature. The adhesion force that holds grain dust particles to the grain itself is an important factor in better understanding and mitigating dust separation from grain kernels and the resulting dust cloud generation. However, that adhesion force, how it is affected by grain quality, and how it is influenced by particle factors such as size and shape has not been adequately researched. A centrifuge separation technique was used to study the adhesion forces of grain dust. Results showed large variability in dust concentration between the five corn samples tested in this study. The dust particle attachment strength ranged from less than 4.6 × 10-10 N to 2.1 × 10-8 N. Only the sample and centrifuge speed interaction had a statistically significant effect on dust concentrations recovered at a 5% confidence limit. Under repeated centrifugations, the dust removed showed a bimodal distribution of attachment strengths, with three of four samples tested showing a local minimum at 2000 rpm, and the other at 3000 rpm. This study improves the understanding of the fundamental attachment strength behind dust separation from grain kernels. Investigating the size, shape, and surface characteristics of dust particles with varying attachment strengths is important to further understand their adhesion and separation mechanisms. Keywords: Adhesion strength, Dust explosion, Dust mitigation, Grain dust, Grain handling.
Application of Modified SME-CN Method for Predicting Event Runoff and Peak Discharge from a Drained Forest Watershed on the North Carolina Atlantic Coastal Plain
Authors: Walega Andrzej , Amatya Devendra M.
Published: May 2020

Highlights

Proposed new method to assess subsurface and surface runoff from drained forested watershed.

Factor Fp in the graphical peak discharge method is less in forested wetland watershed than recommended by USDA.

Modified graphical peak discharge method correctly approximated observed peak discharges.

Abstract. The NRCS curve number (CN) method is a widely used event-based model for estimating runoff using readily available watershed parameters and rainfall data from upland agricultural catchments. However, there is limited literature on application of the CN method in drained forest systems. This study proposes an application of the modified Sahu-Mishra-Eldho (SME) CN method developed and tested in earlier studies. In this study, the SME method was further modified by redefining the maximum potential retention to assess subsurface drainage and surface runoff, which are parts of total outflow, separately for a pine forest watershed with a high water table soil drained by ditches spaced 100 m apart in coastal North Carolina. Assuming that the measured outflow from the drained watershed was dominated by subsurface drainage, computed event outflow using the modified SME-CN (MSME-CN) model showed good agreement with the observed outflow data (without extreme rainfall events) for the study watershed, yielding a Nash-Sutcliffe coefficient of 0.97, R2 = 0.97, and RMSE = 3.46 mm. Linking the direct runoff from the MSME model into the SCS graphical peak discharge method (GPDM) also improved event peak flow estimates compared to those from the GPDM using SCS-CN based outflow, with calculated RMSE of 11.93 and 31.35 L s-1 and modeling efficiency (EF) of 0.79 and -0.45, respectively. In addition, based on analysis, the wetland factor (Fp) of 0.72 recommended in the GPDM was found to be very large and unsuitable for the study watershed with its high retention capacity. The authors suggest multi-site-year validation of the MSME-CN model, which is sensitive to input parameters such as PET5, P, CN, and a, to gain more confidence in it and the associated GPDM. Keywords: Peak discharge, Pine forest, Poorly drained soil, Potential retention, Subsurface runoff, Surface runoff.
O Experimento de Queda de Corpos na Perspectiva Epistemológica
Authors: De Jesus José Carlos Oliveira , Alves Álvaro Santos , Burnham Teresinha Fróes
Published: May 2020

Neste trabalho, discute-se o clássico experimento de queda de corpos segundo uma perspectiva epistemológica, ressaltando-se a colocação do problema físico, a construção de hipóoteses e a escolha dos referenciais teóricos. Enfatiza-se principalmente o papel que esses elementos desempenham na elaboração da metodologia de trabalho experimental, desde a escolha das variáveis relevantes ao contexto teórico em foco, passando pela montagem do experimento até a coleta de dados. Além disso, a análise e discussão dos resultados, bem como a conclusão, estão inapelavelmente ligados ao horizonte teórico previamente estabelecido. As impressões aqui registradas são frutos de uma experiência didática realizada junto a turmas de Física Experimental I do Curso de Graduação em Física da Universidade Estadual de Feira de Santana durante o semestre letivo 2004.2.
Espalhamento inelástico da luz por portadores no plasma em semicondutores. I Cálculo da Função Dielétrica
Authors: Andrade-Neto A. V.
Published: May 2020

Neste trabalho, utilizando a aproximação de banda parabólica, obtemos expressões analíticas para as partes real e imaginária da função dielétrica longitudinal de um plasma em estado sólido no limite de altas temperaturas, onde podemos substituir a função de Fermi-Dirac por uma distribuição dotipo Maxwell-Boltzmann. Em seguida, analisamos seus casos particulares, casos estático e de altas frequências, e recuperamos expressões conhecidas na literatura.
Considerações Gerais sobre o uso da Televisão e do Vídeo na Escola a partir da Experiência de Professores em Sala de Aula no Nível Secundário
Authors: Ribeiro, Miltão Milton Souza , Moraes Simões Maria Tereza , Serra Denise Simões , R. Sousa Tânia Cristina
Published: May 2020

Nesse trabalho, a partir de nossa experiência de professores em sala de aula em uma escola do nível secundário, pretendemos tecer algumas considerações acerca do uso da televisão e do vídeo na escola. O estudo do uso da televisão e do vídeo no 2º grau e tema inserido em vasta bibliografia, contudo os professores desse nível de ensino comparecem, em geral, como objeto de tal estudo e não como autores, pesquisadores dessas investigações. Levando em conta as funções do audiovisual, bem como a linguagem subjacente, estabelecemos uma definição para o audiovisual didático-pedagógico para, em seguida, analisar algumas questões, por nós formuladas, relacionadas ao uso da televisão e do vídeo na sala de aula, tecendo algumas considerações com o objetivo de solucioná-las.
Física Quântica no Espaço de Fase
Authors: Amorim R.G.G.
Published: May 2020

Apresentamos neste trabalho uma revisão bibliográfica sobre Física Quântica no Espaço de Fase. Neste contexto, enfatizamos o método da função de Wigner, que apresenta aplicações em diversas áreas, ao tempo em que demonstramos a importância do mesmo nos estudos das conexões entre as mecânicas quântica e clássica. Nesse sentido, estudamos as propriedades dafunção de Wigner, definimos o produto-estrela e verificamos algumas de suas propriedades. Ainda no contexto do espaço de fase, apresentamos outras funções distribuições, destacando o papel da função de Husimi.
640-nm Pr:YLF regenerative amplifier seeded by gain-switched laser
diode pulses
Authors: Hara Yusaku , Fujita Shogo , Shioya Yuta , Kannari Fumihiko
Published: May 2020

We demonstrated the regenerative amplification of picosecond laser pulses generated by a gain-switched laser diode at 640 nm with a Pr:YLF crystal that was continuously pumped by a multimode blue laser diode. A 0.7-pJ seed pulse energy sufficiently suppressed the self-oscillation in the amplifier. The amplified pulse energy reached 33 µJ at a repetition rate of 10 kHz. The spatial beam quality was nearly

T
E
M

00

. We also demonstrated second- and third-harmonic generation and obtained 320- and 213-nm pulse energies of 18 and 0.83 µJ at 10 kHz.
Calibration methods for a camera with a tilted lens and a three-dimensional laser scanner in the Scheimpflug condition
Authors: Shao Mingwei
Published: May 2020

A three-dimensional laser scanner has been designed and widely utilized in many fields. The lens plane is tilted according to the Scheimpflug condition and the optical axis is not perpendicular to the charge-coupled device plane. In this case, depth of view can be extended significantly. In this paper, analytical models for a camera with a tilted lens and a laser scanner meeting the Scheimpflug condition are presented. Based on these models, a calibration procedure is detailed. We propose a simple calibration method to determine the intrinsic parameters of a Scheimpflug camera. Meanwhile, two calibration methods for a laser scanner in the Scheimpflug condition are detailed. According to the obtained intrinsic parameters, the laser scanner can be calibrated directly. Moreover, a simple calibration for a three-dimensional laser scanner without the help of a precise positioning system is described. Experimental results show the effectiveness and high measurement accuracy of our calibration methods.
Distribution of optical-comb-based multi-frequency microwave signals over 100 km optical fiber with high phase stability
Authors: Deng Nan , Wei Wei , Liu Zhangweiyi , Xie Weilin , Dong Yi
Published: May 2020

We demonstrate a long-distance multi-frequency microwave distribution system over an optical fiber link with high phase stability based on transferring an optical frequency comb (OFC). The phase fluctuation induced by the transmission link variations is detected by applying a reference OFC and is then compensated with the proposed optical voltage-controlled oscillator (OVCO) by adjusting the phase of the repetition rate of the transmitted OFC. By applying the OVCO, we perform the OFC-based multi-frequency microwave distribution over a 100 km standard single-mode fiber. The performance of the transmission system can be exhibited by evaluating the repetition rate (10.015 GHz) and second harmonic frequency (20.03 GHz) signals achieved at the remote end. The residual phase noise of the 10.015 GHz and 20.03 GHz signal is −64 dBc/Hz and −58 dBc/Hz at 1 Hz frequency offset from the carrier, respectively. The fractional frequency instability is 1.4×10−16 and 2.4×10−16 at 10000 s averaging time, respectively. And the timing jitter in the frequency range from 0.01 Hz to 1 MHz reaches 88 fs and 87 fs, respectively. Based on the phase-locked loop theory, we conduct a simulation model of the transmission system and the simulated results match well with experiments. It shows that by detecting the phase fluctuation with higher harmonic frequency signals in the simulation system, the performance of the transmission system can be further improved.
Synthetic spectra generated by boundary equilibrium generative adversarial networks and their applications with consensus algorithms
Authors: Zhu Dehua , Xu Lingjie , Chen Xiaojing , Yuan Lei-ming , Huang Guangzao , Li Limin , Chen Xi , Shi Wen
Published: May 2020

One of the major restrictions in spectroscopic analysis is the limited number of calibrations, especially for biological samples. Meanwhile, there is a lack of effective algorithms to simulate synthetic spectra from the real spectra of limited samples. Thus in this work, a boundary equilibrium generative adversarial network (BEGAN) was proposed to automatically generate synthetic spectra and successfully produce spectra from two datasets. Then, the impact of the diversity ratio was estimated in the aspect of the quality and diversity of the generated spectra by BEGAN, and a negative correlation was found between quality and diversity. Finally, these synthetic spectra are applied in a consensus algorithm named creating diversity partial least squares (CDPLS) to replenish virtual samples in every iteration. Results show that the synthetic spectra generated by BEGAN are of high quality and improve the predictive performance of CDPLS. It can concluded that BEGAN has the potential to generate derived homologous spectra and expand the number of spectra in some small sample sets.
Second-order optimized regularized structured illumination microscopy (sorSIM) for high-quality and rapid super resolution image reconstruction with low signal level
Authors: Yu Wei , Li Yangyang , Jooken Stijn , Deschaume Olivier , Liu Fei , Wang Shouyu , Bartic Carmen
Published: May 2020

Structured illumination microscopy (SIM) is a widely used super resolution imaging technique that can down-modulate a sample’s high-frequency information into objective recordable frequencies to enhance the resolution below the diffraction limit. However, classical SIM image reconstruction methods often generate poor results under low illumination conditions, which are required for reducing photobleaching and phototoxicity in cell imaging experiments. Although denoising methods or auxiliary items improved SIM image reconstruction in low signal level situations, they still suffer from decreased reconstruction quality and significant background artifacts, inevitably limiting their practical applications. In order to improve the reconstruction quality, second-order optimized regularized SIM (sorSIM) is designed specifically for image reconstruction in low signal level situations. In sorSIM, a second-order regularization term is introduced to suppress noise effect, and the penalty factor in this term is selected to optimize the resolution enhancement and noise resistance. Compared to classical SIM image reconstruction algorithms as well as to those previously used in low illumination cases, the proposed sorSIM provides images with enhanced resolution and fewer background artifacts. Therefore, sorSIM can be a potential tool for high-quality and rapid super resolution imaging, especially for low signal images.
Ghost imaging based on Y-net: a dynamic coding and decoding approach
Authors: Zhu Ruiguo , Yu Hong , Tan Zhijie , Lu Ronghua , Han ShenSheng , Huang Zengfeng , Wang Jian
Published: May 2020

Ghost imaging incorporating deep learning technology has recently attracted much attention in the optical imaging field. However, deterministic illumination and multiple exposure are still essential in most scenarios. Here we propose a ghost imaging scheme based on a novel dynamic decoding deep learning framework (Y-net), which works well under both deterministic and indeterministic illumination. Benefited from the end-to-end characteristic of our network, the image of a sample can be achieved directly from the data collected by the detector. The sample is illuminated only once in the experiment, and the spatial distribution of the speckle encoding the sample in the experiment can be completely different from that of the simulation speckle in training, as long as the statistical characteristics of the speckle remain unchanged. This approach is particularly important to high-resolution x-ray ghost imaging applications due to its potential for improving image quality and reducing radiation damage.
Tuning Anderson localization of edge-mode graphene plasmons in randomly gated nanoribbons
Authors: Zhu Yingying , Li Chang-Gui , Zhu Yi , Xiong Bo , Peng Ruwen , Wang Mu
Published: May 2020

Edge-mode graphene plasmons (EGPs) supported by graphene nanoribbons are highly confined, and they can show versatile tunability under electrostatic bias. In order to efficiently enhance and actively control the near-field intensity in integrated plasmonic devices, we theoretically study Anderson localization of EGPs in a graphene nanoribbon with an underlying electrode array in this work. By randomly arranging the electrodes in the array, positional disorder is introduced in the graphene nanoribbon system. Consequently, the Anderson localization of EGPs occurs with an exponentially decreased electric field, reduced propagation length, and rapid disappearance of the cross-correlation coefficient. Physically, inhomogeneous gating effectively creates a disordered distribution of Fermi levels in the graphene nanoribbon, which provides adequate fluctuation of the effective refractive index and results in strong localization of the EGPs at mid-infrared regime. By changing electrode array arrangements, the EGPs can be trapped at distinct locations in the nanoribbon. Further considering that the Fermi-level disorder can be introduced by randomly modulating the electrostatic bias, we apply different gate voltages at different electrodes in the array. Electrically tunable Anderson localization of EGPs are eventually realized in those randomly gated nanoribbons. Moreover, by combining both the positional and Fermi-level disorders in the system, the Anderson localization becomes more actively controlled in this electrically gated graphene nanoribbons. It is shown that the local field can be selectively trapped at single distinct location, or even several locations along the graphene nanoribbon. This investigation extends the Anderson localization to the EGPs in the mid-infrared range and enriches the graphene-based active plasmonic devices.
Theoretical analysis of compact ultrahigh-spectral-resolution infrared imaging spectrometer
Authors: Yang Qinghua
Published: May 2020

A compact ultrahigh-spectral-resolution imaging spectrometer (CUSRIS) is presented, which combines an entrance slit, a scanning Fabry-Perot interferometer (FPI), a static grating interferometer (SGI) and a cylindrical lens. The SGI consists of a beam splitter, a fixed reflection grating in Littrow configuration, and a fixed plane mirror. For each point of the entrance slit, one spectral image is obtained at each FPI spacing position, and multiple spectral images are obtained to synthesize an ultrahigh-spectral-resolution spectral image. First-order approximations of system performance are given. The CUSRIS is a unique concept that not only obtains spatial information and ultrahigh-resolution spectral information (e.g., resolving power higher than 1,000,000) in the near-infrared, short-wave infrared or mid-wave infrared region, but also has the advantages of compact size and short measurement time compared with the existing ultrahigh-spectral-resolution infrared imaging spectrometers.
Computational Optical Sensing and Imaging: feature issue introduction
Authors: Harvey Andrew R. , Cossairt Oliver , Ke Jun , Lam Edmund Y. , Rangarajan Prasanna
Published: May 2020

This Feature Issue includes 19 articles that highlight advances in the field of Computational Optical Sensing and Imaging. Many of the articles were presented at the 2019 OSA Topical Meeting on Computational Optical Sensing and Imaging held in Munich, Germany, on June 24–27. Articles featured in the issue cover a broad array of topics ranging from imaging through scattering media, imaging round corners and compressive imaging to machine learning for recovery of images.
Stimulated Brillouin scattering in a tapered dual-core As2Se3-PMMA fiber for simultaneous temperature and strain sensing
Authors: Wang Haiyang , Gao Song , Baker Chams , Wang Yuan , Chen Liang , Bao Xiaoyi
Published: May 2020

Chalcogenide fibers are currently being used widely in nonlinear optical signal processing, as they exhibit ultrahigh nonlinearity. Here, we propose a sensor based on stimulated Brillouin scattering for simultaneous temperature and strain measurement in a dual-core tapered

A
s

2

S
e

3

-polymethyl methacrylate fiber using a Brillouin optical time-domain analysis system. Different Brillouin frequency responses under temperature and strain variations and the separation of Brillouin frequency shifts (BFSs) in two principal polarization axes are demonstrated experimentally over a 50-cm-long tapered dual-core hybrid microfiber. The temperature coefficients are

−

3.8272

M
H
z

/

∘

C

and

−

3.3302

M
H
z

/

∘

C

, and the strain coefficients are

−

0.06143

M
H
z

/

µ
ε

and

−

0.03463

M
H
z

/

µ
ε

. Due to the different temperature and strain dependences of Brillouin frequency peaks in two polarizations, temperature and strain resolutions of 1°C and

33

µ
ε

are realized, respectively. Numerical simulations are also reported to account for the BFS difference in two polarization axes.
Occlusion-capable optical-see-through near-eye display using a single digital micromirror device
Authors: Ju Yeon-Gyeong , Choi Myeong-Ho , Liu Pengyu , Hellman Brandon , Lee Ted L. , Takashima Yuzuru , Park Jae-Hyeung
Published: May 2020

Occlusion of a real scene by displayed virtual images mitigates
incorrect depth cues and enhances image visibility in augmented
reality applications. In this Letter, we propose a novel optical
scheme for the occlusion-capable optical-see-through near-eye display.
The proposed scheme uses only a single spatial light modulator, as the
real-scene mask and virtual image display simultaneously. A
polarization-based double-pass configuration is also combined,
enabling a compact implementation. The proposed scheme is verified by
optical experiments which demonstrate a 60 Hz red-green-blue video
display with a 4-bit depth for each color channel and per-pixel
dynamic occlusion of a 90.6% maximum occlusion ratio.
Intravital confocal fluorescence lifetime imaging microscopy in the second near-infrared window
Authors: Yu Jia , Zhang Rongli , Gao Yufeng , Sheng Zonghai , Gu Min , Sun Qinchao , Liao Jiuling , Wu Ting , Lin Zhanyi , Wu Peiheng , Kang Lin , Li Hui , Zhang Labao , Zheng Wei
Published: May 2020

We present confocal fluorescence lifetime imaging microscopy in the second near-infrared (NIR-II) window to assess the morphological and biochemical information of live samples. A home-built superconducting single-photon detector (SSPD) was used to facilitate the NIR-II fluorescence lifetime measurement. The SSPD has many advantages, including high sensitivity to NIR-II signals (detection efficiency

>

50

%

), fast temporal response (

∼

109

p
s

), low timing jitter (

∼

50

p
s

), and low dark count rate (

<

100

c
p
s

). We demonstrate the feasibility of the developed microscopy system by comparing fluorescence lifetimes of a range of fluorophores with emission in the NIR-II window and by performing multicolor three-dimensional fluorescence lifetime imaging of a mouse ear in vivo. The biochemical properties of the cells and tissues probed by the fluorescence lifetimes of the fluorophores provide complementary information for biomedical studies, significantly benefiting diverse applications in life science.
Portable broadband photoacoustic spectroscopy for trace gas detection by quantum cascade laser arrays
Authors: Liao Chien-Sheng , Blanchard Romain , Pfluegl Christian , Azimi Masud , Huettig Fred , Vakhshoori Daryoosh
Published: May 2020

We report a portable broadband photoacoustic spectroscopic system for trace gas detection using distributed feedback quantum cascade laser arrays. By sequentially firing 128 lasers, our system acquires a photoacoustic spectrum covering

565

c
m

−
1

(

935

−

1500

c
m

−
1

) with a normalized-noise-equivalent-absorption coefficient of

2.5

×

10

−
9

c
m

−
1

W
H
z

−
1

/

2

. The firing sequence that determines when and which laser to activate is programmable, which enables frequency-multiplexing excitation. For demonstration, 12 lasers are modulated simultaneously at distinct frequencies, and a photoacoustic spectrum is acquired within 13 ms. The compactness (

28

c
m

×

17

c
m

×

13

c
m

, 3.5 kg) and low power consumption enable convenient installation for on-site monitoring.