bluuebunny/crossref_metadata_2025 huggingface dataset:
DKK3 attenuates JNK and AP-1 induced inflammation via Kremen-1 and DVL-1 in mice following intracerebral hemorrhage
Authors: Xu Yang , Nowrangi Derek , Liang Hui , Wang Tian , Yu Lingyan , Lu Tai , Lu Zhengyang , Zhang John H. , Luo Benyan , Tang Jiping
Published: April 2020

Background

Intracerebral hemorrhage (ICH) is the most devastating stroke subtype, with a poor prognosis and few proven treatments. Neuroinflammation is associated with ICH-induced brain injury and unfavorable outcomes. There is growing evidence that Dickkopf (DKK) 3 plays a key role in the adaptive anti-inflammatory and neuroprotective responses following intracerebral hemorrhage. This study aimed to evaluate the protective effects of DKK3 against brain edema and neuroinflammation in a mice model of ICH.

Methods

Male, adult CD1 mice were subjected to sham or ICH surgery using a collagenase injection model. ICH animals received either recombinant DKK3, Kremen-1 siRNA, or DVL-1 siRNA. The neurobehavioral deficits were evaluated at 24 h, 72 h, and 28 days after ICH induction. Western blot and immunofluorescence were employed to examine the expression and localization of DKK3, Kremen-1, Dishevelled-1 (DVL-1), c-JUN N-terminal kinase (JNK), Activator protein-1 (AP-1), cleaved caspase-1, NF-κB, and IL-1β in the brain.

Results

The expression of endogenous DKK3 and DVL-1 was transiently decreased after ICH compared to that in the sham group. Compared to the mice of ICH, exogenous rDKK3 administration reduced the brain water content and affected the neurological functions in ICH mice. Moreover, DKK3 was colocalized with Kremen-1 in microglia. Using a Kremen-1 or DVL-1 siRNA-induced in vivo knockdown approach, we demonstrated that the effects of DKK3 against ICH were mediated, at least partly, by the Kremen-1 and DVL-1 pathways.

Conclusions

DKK3 improves the neurological outcomes, potentially by decreasing JNK/AP-1-mediated inflammation, thereby ameliorating the short- and long-term sequelae after ICH.
Inhibition of formyl peptide receptors improves the outcome in a mouse model of Alzheimer disease
Authors: Schröder Nicole , Schaffrath Anja , Welter Josua A. , Putzka Tim , Griep Angelika , Ziegler Patrick , Brandt Elisa , Samer Sebastian , Heneka Michael T. , Kaddatz Hannes , Zhan Jiangshan , Kipp Eugenia , Pufe Thomas , Tauber Simone C. , Kipp Markus , Brandenburg Lars-Ove
Published: April 2020

Background

An important hallmark of Alzheimer’s disease (AD) is the increase of Aβ1-42 burden and its accumulation to senile plaques, leading the reactive gliosis and neurodegeneration. The modulation of glia cell function represents an attractive therapeutic strategy, but is currently limited by an incomplete understanding of its relevance for AD. The chemotactic G-protein coupled formyl peptide receptor (FPR), which is known to modulate Aβ1-42 uptake and signal transduction, might be one candidate molecule regulating glia function in AD. Here, we investigate whether the modulation of FPR exerts beneficial effects in an AD preclinical model.

Methods

To address this question, APP/PS1 double-transgenic AD mice were treated for 20 weeks with either the pro-inflammatory FPR agonist fMLF, the FPR1/2 antagonist Boc2 or the anti-inflammatory FPR2 agonist Ac2-26. Spatial learning and memory were evaluated using a Morris water maze test. Immunohistological staining, gene expression studies, and flow cytometry analyses were performed to study neuronal loss, gliosis, and Aß-load in the hippocampus and cortex, respectively.

Results

FPR antagonism by Boc2-treatment significantly improved spatial memory performance, reduced neuronal pathology, induced the expression of homeostatic growth factors, and ameliorated microglia, but not astrocyte, reactivity. Furthermore, the elevated levels of amyloid plaques in the hippocampus were reduced by Boc2-treatment, presumably by an induction of amyloid degradation.

Conclusions

We suggest that the modulation of FPR signaling cascades might be considered as a promising therapeutic approach for alleviating the cognitive deficits associated with early AD. Additional studies are now needed to address the downstream effectors as well as the safety profile of Boc2.
Remotely monitoring ecosystem respiration from various grasslands along a large-scale east–west transect across northern China
Authors: Tang Xuguang , Zhou Yanlian , Li Hengpeng , Yao Li , Ding Zhi , Ma Mingguo , Yu Pujia
Published: April 2020

Background

Grassland ecosystems play an important role in the terrestrial carbon cycles through carbon emission by ecosystem respiration (Re) and carbon uptake by plant photosynthesis (GPP). Surprisingly, given Re occupies a large component of annual carbon balance, rather less attention has been paid to developing the estimates of Re compared to GPP.

Results

Based on 11 flux sites over the diverse grassland ecosystems in northern China, this study examined the amounts of carbon released by Re as well as the dominant environmental controls across temperate meadow steppe, typical steppe, desert steppe and alpine meadow, respectively. Multi-year mean Re revealed relatively less CO2 emitted by the desert steppe in comparison with other grassland ecosystems. Meanwhile, C emissions of all grasslands were mainly controlled by the growing period. Correlation analysis revealed that apart from air and soil temperature, soil water content exerted a strong effect on the variability in Re, which implied the great potential to derive Re using relevant remote sensing data. Then, these field-measured Re data were up-scaled to large areas using time-series MODIS information and remote sensing-based piecewise regression models. These semi-empirical models appeared to work well with a small margin of error (R2 and RMSE ranged from 0.45 to 0.88 and from 0.21 to 0.69 g C m−2 d−1, respectively).

Conclusions

Generally, the piecewise models from the growth period and dormant season performed better than model developed directly from the entire year. Moreover, the biases between annual mean Re observations and the remotely-derived products were usually within 20%. Finally, the regional Re emissions across northern China’s grasslands was approximately 100.66 Tg C in 2010, about 1/3 of carbon fixed from the MODIS GPP product. Specially, the desert steppe exhibited the highest ratio, followed by the temperate meadow steppe, typical steppe and alpine meadow. Therefore, this work provides a novel framework to accurately predict the spatio-temporal patterns of Re over large areas, which can greatly reduce the uncertainties in global carbon estimates and climate projections.
Reduction of NgR in perforant path decreases amyloid-β peptide production and ameliorates synaptic and cognitive deficits in APP/PS1 mice
Authors: Jiang Rong , Wu Xue-Fei , Wang Bin , Guan Rong-Xiao , Lv Lang-Man , Li Ai-Ping , Lei Lei , Ma Ye , Li Na , Li Qi-Fa , Ma Quan-Hong , Zhao Jie , Li Shao
Published: April 2020

Background

Amyloid beta (Aβ) which is recognized as a main feature of Alzheimer’s disease (AD) has been proposed to “spread” through anatomically and functionally connected brain regions. The entorhinal cortex and perforant path are the earliest affected brain regions in AD. The perforant path is the most vulnerable circuit in the cortex with respect to both aging and AD. Previous data show that the origins and terminations of the perforant path are susceptible to amyloid deposition at the younger age in AD. Nogo receptor (NgR) plays an essential role in limiting injury-induced axonal growth and experience-dependent plasticity in the adult brain. It has been suggested that NgR is involved in AD pathological features, but the results have been conflicting and the detailed mechanism needs further investigation. In this study, the effect of NgR in the perforant path on the pathological and functional phenotype of APP/PS1 transgenic mice was studied.

Methods

To genetically manipulate NgR expression, adeno-associated virus (AAV) with short hairpin (shRNA) against NgR was injected into the perforant path of APP/PS1 transgenic mice, followed by an assessment of behavioral, synaptic plasticity and neuropathological phenotypes. NgR was overexpressed or knockdown in neuroblastoma N2a cells and APPswe/HEK293 cells to investigate the interaction between NgR and amyloid precursor protein (APP).

Results

It is shown that reduction of NgR in the perforant path rescued cognitive and synaptic deficits in APP/PS1 transgenic mice. Concurrently, Aβ production in the perforant path and levels of soluble Aβ and amyloid plaques in the hippocampus were significantly decreased. There was a positive correlation between the total APP protein level and NgR expression both in transgenic mice and in cultured cells, where the α-secretase and β-secretase cleavage products both changed with APP level in parallel. Finally, NgR might inhibit APP degradation through lysosome by Rho/Rho-associated protein kinases (ROCK) signaling pathway.

Conclusions

Our findings demonstrate that perforant path NgR plays an important role in regulating APP/Aβ level and cognitive functions in AD transgenic mice, which might be related to the suppression of APP degradation by NgR. Our study suggests that NgR in the perforant path could be a potential target for modulating AD progression.
A systematic review and taxonomy of tools for evaluating evidence-based medicine teaching in medical education
Authors: Kumaravel Bharathy , Hearn Jasmine Heath , Jahangiri Leila , Pollard Rachel , Stocker Claire J. , Nunan David
Published: April 2020

Background

The importance of teaching the skills and practice of evidence-based medicine (EBM) for medical professionals has steadily grown in recent years. Alongside this growth is a need to evaluate the effectiveness of EBM curriculum as assessed by competency in the five ‘A’s’: asking, acquiring, appraising, applying and assessing (impact and performance). EBM educators in medical education will benefit from a compendium of existing assessment tools for assessing EBM competencies in their settings. The purpose of this review is to provide a systematic review and taxonomy of validated tools that evaluate EBM teaching in medical education.

Methods

We searched MEDLINE, EMBASE, Cochrane library, Educational Resources Information Centre (ERIC), Best Evidence Medical Education (BEME) databases and references of retrieved articles published between January 2005 and March 2019. We have presented the identified tools along with their psychometric properties including validity, reliability and relevance to the five domains of EBM practice and dimensions of EBM learning. We also assessed the quality of the tools to identify high quality tools as those supported by established interrater reliability (if applicable), objective (non-self-reported) outcome measures and achieved ≥ 3 types of established validity evidence. We have reported our study in accordance with the PRISMA guidelines.

Results

We identified 1719 potentially relevant articles of which 63 full text articles were assessed for eligibility against inclusion and exclusion criteria. Twelve articles each with a unique and newly identified tool were included in the final analysis. Of the twelve tools, all of them assessed the third step of EBM practice (appraise) and four assessed just that one step. None of the twelve tools assessed the last step of EBM practice (assess). Of the seven domains of EBM learning, ten tools assessed knowledge gain, nine assessed skills and-one assessed attitude. None addressed reaction to EBM teaching, self-efficacy, behaviours or patient benefit. Of the twelve tools identified, six were high quality. We have also provided a taxonomy of tools using the CREATE framework, for EBM teachers in medical education.

Conclusions

Six tools of reasonable validity are available for evaluating most steps of EBM and some domains of EBM learning. Further development and validation of tools that evaluate all the steps in EBM and all educational outcome domains are needed.

Systematic review registration

PROSPERO CRD42018116203.
The Samuelson macroeconomic model as a singular linear matrix difference equation
Authors: Ortega Fernando , Barros Maria Filomena
Published: April 2020

In this paper, we revisit the famous classical Samuelson’s multiplier–accelerator model for national economy. We reform this model into a singular discrete time system and study its solutions. The advantage of this study gives a better understanding of the structure of the model and more deep and elegant results.
Behavioral rhythms of an opportunistic predator living in anthropogenic landscapes
Authors: Parra-Torres Yaiza , Ramírez Francisco , Afán Isabel , Aguzzi Jacopo , Bouten Willem , Forero Manuela G. , Navarro Joan
Published: April 2020

Background

Human activities have profoundly altered the spatio-temporal availability of food resources. Yet, there is a clear lack of knowledge on how opportunistic species adapt to these new circumstances by scheduling their daily rhythms and adjust their foraging decisions to predicable patterns of anthropic food subsidies. Here, we used nearly continuous GPS tracking data to investigate the adaptability of daily foraging activity in an opportunistic predator, the yellow-legged gull (Larus michahellis), in response to human schedules.

Methods

By using waveform analysis, we compared timing and magnitude of peaks in daily activity of different GPS-tracked individuals in eleven different habitat types, in relation to type of day (i.e., weekday vs. weekend).

Results

Daily activity rhythms varied greatly depending on whether it was a weekday or weekend, thus suggesting that gulls’ activity peaks matched the routines of human activity in each habitat type. We observed for the first time two types of activity as modelled by waveforms analysis: marine habitats showed unimodal patterns with prolonged activity and terrestrial habitats showed bimodal patterns with two shorter and variable activity peaks.

Conclusions

Our results suggest that gulls are able to fine-tune their daily activity rhythms to habitat-specific human schedules, since these likely provide feeding opportunities. Behavioral plasticity may thus be an important driver of expansive population dynamics. Information on predictable relationships between daily activity patterns of gulls and human activities is therefore relevant to their population management.
Predicting Cancer Cell Line Dependencies From the Protein Expression Data of Reverse-Phase Protein Arrays
Authors: Chen Mei-Ju May , Li Jun , Mills Gordon B. , Liang Han
Published: April 2020

PURPOSE

Predicting cancer dependencies from molecular data can help stratify patients and identify novel therapeutic targets. Recently available data on large-scale cancer cell line dependency allow a systematic assessment of the predictive power of diverse molecular features; however, the protein expression data have not been rigorously evaluated. By using the protein expression data generated by reverse-phase protein arrays, we aimed to assess their predictive power in identifying cancer dependencies and to develop a related analytic tool for community use.

MATERIALS AND METHODS

By using a machine learning schema, we conducted an analysis of feature importance based on cancer dependency and multiomic data from the DepMap and Cancer Cell Line Encyclopedia projects. We assessed the consistency of cancer dependency data between CRISPR/Cas9 and short hairpin RNA–mediated perturbation platforms. For a fair comparison, we focused on a set of genes with robust dependency data and four available expression-related features (copy number alteration, DNA methylation, messenger RNA expression, and protein expression) and performed the same-gene predictions of the cancer dependency using different molecular features.

RESULTS

For the genes surveyed, we observed that the protein expression data contained substantial predictive power for cancer dependencies, and they were the best predictive feature for the CRISPR/Cas9-based dependency data. We also developed a user-friendly protein-dependency analytic module and integrated it with The Cancer Proteome Atlas; this module allows researchers to explore and analyze our results intuitively.

CONCLUSION

This study provides a systematic assessment for predicting cancer dependencies of cell lines from different expression-related features of a gene. Our results suggest that protein expression data are a highly valuable information resource for understanding tumor vulnerabilities and identifying therapeutic opportunities.
Consistent Physical Activity and Future Neurocognitive Problems in Adult Survivors of Childhood Cancers: A Report From the Childhood Cancer Survivor Study
Authors: Barlow-Krelina Emily , Chen Yan , Yasui Yutaka , Till Christine , Gibson Todd M. , Ness Kirsten K. , Leisenring Wendy M. , Howell Rebecca M. , Nathan Paul C. , Oeffinger Kevin C. , Robison Leslie L. , Armstrong Gregory T. , Krull Kevin R. , Edelstein Kim
Published: April 2020

PURPOSE

To investigate longitudinal associations between physical activity (PA) and neurocognitive problems in adult survivors of childhood cancer.

METHODS

A total of 12,123 5-year survivors diagnosed between 1970 and 1999 (median [range] age at diagnosis, 7 [0-21] years, time since diagnosis at baseline, 16 [6-30] years) and 720 siblings self-reported PA and neurocognitive problems. PA was collected at baseline, and PA and neurocognitive data were obtained 7 (1-12) years and 12 (9-14) years later. PA consistency was defined as any combination of ≥ 75 minutes of vigorous or 150 minutes of moderate activity per week on all surveys. Multiple linear regressions, conducted separately for CNS and non-CNS survivors, identified associations between PA consistency and neurocognitive outcomes (expected mean, 50; standard deviation [SD], 10). Mediating effects of body mass index (BMI) and chronic health conditions (CHCs) were evaluated.

RESULTS

Survivors were less likely than siblings to report consistent PA (28.1% v 33.6%) and more likely to report problems in Task Efficiency (T-scores mean ± SD: siblings, 50.0 ± 0.4; CNS, 61.4 ± 0.4; non-CNS, 53.3 ± 0.3), Emotion Regulation (siblings, 51.4 ± 0.4; CNS, 54.5 ± 0.3; non-CNS 53.4 ± 0.2), and Memory (siblings, 50.8 ± 0.4; CNS, 58.9 ± 0.4; non-CNS, 53.5 ± 0.2; all P < .001). Survivors of CNS cancers (52.8 ± 0.3) also reported poorer Organization than siblings (49.9 ± 0.4; P < .001). After adjusting for age at diagnosis, age at questionnaire, emotional distress, and cancer treatment exposures, consistent PA was associated with fewer neurocognitive problems compared with consistent inactivity for both CNS and non-CNS groups (T-score differences ranging from −7.9 to −2.2) and larger neurocognitive improvements over time (−6.0 to −2.5), all P ≤ .01. BMI and severe CHCs partially mediated the PA-neurocognitive associations, but the mediation effects were small (change in β ≤ 0.4).

CONCLUSION

Adult survivors of childhood cancer who report more consistent PA have fewer neurocognitive problems and larger improvements in these concerns many years after treatment.
The Agency of the Mob in Joseph Andrews and A True State of the Case of Bosavern Penlez
Authors: Fleming Catherine
Published: April 2020

In his novels and pamphlets, Henry Fielding promotes a hierarchical structure that suppresses the common people. But his writings, especially his novel Joseph Andrews, his pamphlets, the 1749 A True State of the Case of Bosavern Penlez and the 1751 Enquiry into the Causes of the Late Increase of Robbers, and his newspaper, the Covent Garden Journal, also display a certainty that the poor possessed both power and agency. He encouraged all citizens to take part in legal actions from policing to prosecuting. This essay argues that while he condemns citizens who attempt to change the law, he also calls on them to take a greater part in enforcing them.
Squaring the EMC – how promoting membrane protein biogenesis impacts cellular functions and organismal homeostasis
Authors: Volkmar Norbert , Christianson John C.
Published: April 2020

Integral membrane proteins play key functional roles at organelles and the plasma membrane, necessitating their efficient and accurate biogenesis to ensure appropriate targeting and activity. The endoplasmic reticulum membrane protein complex (EMC) has recently emerged as an important eukaryotic complex for biogenesis of integral membrane proteins by promoting insertion and stability of atypical and sub-optimal transmembrane domains (TMDs). Although confirmed as a bona fide complex almost a decade ago, light is just now being shed on the mechanism and selectivity underlying the cellular responsibilities of the EMC. In this Review, we revisit the myriad of functions attributed the EMC through the lens of these new mechanistic insights, to address questions of the cellular and organismal roles the EMC has evolved to undertake.
Doenças respiratórias no Triângulo Mineiro: Análise epidemiológica e projetiva com a pandemia de COVID-19
Authors: Dias Fellipe Leonardo Torres , Mendonça Flávia Daspett , Pinto Gabriela Mori , Borges Isabela Souza Cruvinel , Oliveira Stefan Vilges de
Published: April 2020

Objetivos: investigar as internações por doenças respiratórias no Triângulo Mineiro (Minas Gerais, Brasil), discutindo-as no contexto da atenção em saúde, e a pandemia de COVID-19. Métodos: estudo epidemiológico, descritivo e quantitativo sobre as doenças do aparelho respiratório nas macrorregiões de saúde Triângulo do Norte e Triângulo do Sul, de janeiro de 2014 a dezembro de 2019. Foram utilizados dados provenientes do Sistema de Informação Hospitalar do Sistema Único de Saúde (SIH/SUS), disponíveis no endereço eletrônico do Departamento de Informática do SUS (DATASUS). Os dados foram apresentados por números absolutos, frequência relativa e medidas de tendência central. Resultados: nesse período, houve 76.745 internações por doenças do aparelho respiratório no Sistema Único de Saúde (SUS), com aspecto crescente desde 2018. As cidades de Uberlândia e Uberaba somam juntas quase metade desse total. Com os serviços hospitalares e profissionais foram gastos, aproximadamente, 90 milhões de reais. As faixas etárias cuja internação foi mais frequente foram a de 1 a 4 anos e a de 80 anos ou mais. As maiores frequências de óbitos concentraram-se no segundo e terceiro trimestre do ano e entre os indivíduos acima de 60 anos. Conclusões: O contexto caótico e oneroso ao SUS, decorrente das internações por doenças respiratórias, agravar-se-á ao se somar ao cenário de pandemia por COVID-19. Por isso, é imperiosa a prevenção dos fatores de risco e a promoção de saúde por meio da melhora na atenção primária em saúde, bem como a ampliação e a reorganização da rede hospitalar.
Administrative law. Workshop
Authors: Zaykova Svetlana
Published: April 2020

A workshop on the subject "Administrative law" at the undergraduate, master's and specialist program covers 14 topics (General part of administrative law) and contains plans of practical classes, the list of normative legal and other legal acts, recommended literature, test questions, legal issues, practical, creative and test tasks, exercises for work with scientific articles, themes, essays, reports, control and course works, final works.
Developed taking into account Federal state educational standards of higher education of the last generation in the direction of training 40.03.01 "Jurisprudence" and the specialty 40.05.04 "Judicial and prosecutorial activities."
For students of law faculties of educational institutions of higher education, teachers of disciplines of "Administrative law", "Administrative process", "Administrative responsibility," researchers and practitioners, and a wide range of readers interested in administrative law.
Nasal fractures: a dedicated clinic providing reduction under local anaesthesia improves time to manipulation
Authors: Pinto R , Wright R , Ghosh S
Published: April 2020

Introduction

Guidelines for nasal injury state that assessment should be at 7–10 days post-injury and manipulation within 14 days. We performed a plan, do, study, act improvement cycle to assess whether a dedicated nasal fracture service led to better outcomes.

Materials and methods

A retrospective study was carried out of all patients undergoing manipulation under anaesthesia for nasal trauma between February 2013 and December 2016 in a district general hospital. A dedicated nasal fracture clinic providing manipulation under local anaesthesia was implemented followed by a prospective study of all patients presenting to the clinic between February and November 2017. Main outcome measures included time from injury to otolaryngology assessment, time from injury to manipulation and incidence of secondary septorhinoplasty.

Results

The retrospective series involved 525 patients including 381 males (72.6%) and 144 females (27.4%). Mean time from injury to assessment was 10 days. Mean time from injury to surgery was 14.5 days. Mean time from assessment to surgery was five days. The incidence of septorhinoplasty was 2.3%. The prospective series involved 119 patients including 78 males (65.5%) and 41 females (34.5%). Following implementation of a nasal fracture clinic, mean time from injury to assessment and manipulation was 6.1 days and 5.4% of patients underwent septorhinoplasty for secondary deformity.

Discussion

Implementation of a nasal fracture clinic providing reduction under local anaesthesia reduced the time to assessment and manipulation. The incidence of septorhinoplasty is low following reduction under general or local anaesthesia. Assessment earlier than seven days is feasible and advice for referral can be changed accordingly.
Immediate unilateral breast reconstruction and contralateral breast augmentation with bilateral free deep inferior epigastric perforator flaps
Authors: Khatib M , Wong KY , Elfaki A , Haywood RM , Masud D
Published: April 2020

A 42-year-old woman was referred for consideration of left-sided mastectomy and immediate reconstruction. She previously had a bilateral breast augmentation using silicone implants. She desired to maintain her breast size and natural appearance. Owing to the availability of sufficient abdominal tissue, the option of an immediate unilateral breast reconstruction and contralateral augmentation with a differentially split deep inferior epigastric perforator flaps was offered to the patient. The patient had a successful reconstructive and contralateral symmetrising procedure with an uneventful postoperative recovery. She was satisfied with her breast size, which was achieved without the use of implants. In selected patients the free deep inferior epigastric perforator flap provides an appropriate option for unilateral breast reconstruction and contralateral breast augmentation. It has numerous advantages including making use of available excess abdominal tissue and avoiding implant related complications.
Laparoscopic repair of a giant hiatal hernia after minimally invasive oesophagectomy
Authors: Marchesi F , Dalmonte G , Morini A , Annicchiarico A
Published: April 2020

Minimally invasive oesophagectomy has become popular, but studies showed a higher rate of postoperative hiatus hernia compared with open oesophagectomy. Our video presents the laparoscopic biosynthetic mesh repair of a symptomatic giant hiatus hernia in a 71-year-old man who had undergone minimally invasive oesophagectomy one year earlier for distal adenocarcinoma of the oesophagus. The operative time was 120 minutes. The patient started oral intake on postoperative day one and was discharged on postoperative day three. Postoperative computed tomography at six months showed no signs of recurrence. In the setting of a symptomatic hiatus hernia post-minimally invasive oesophagectomy, we suggest an initial laparoscopic approach, because of its countless advantages.
Intensity-modulated bend sensor by using a twin core fiber: theoretical and experimental studies
Authors: Yin Guolu , Zhang Fengchan , Xu Baijie , He Jun , Wang Yiping
Published: April 2020

A new optical fiber bend sensor is proposed and demonstrated based on a sandwich structure created by splicing a segment of twin core fiber (TCF) between two segments of single mode fibers (SMFs). One core of the TCF is aligned with the cores of two segments of SMFs. An incident beam is directed into the TCF by the lead-in SMF. Light couples back and forth between two cores. The bend sensing performance of the sensor is investigated by intensity-modulated method. The intensity of the operation wavelength is modulated by the change of refractive index and geometrical deformation in the bent TCF. Experimental results show such a bend sensor achieves sensitivity of +0.671 /m−1 and resolution of 0.003 m−1 in the range of 0 to 1.25 m−1. In addition, the sensitivity and bend measurement range can be flexibly adjusted through selection of the length of TCF and sensing configuration. As such, the proposed sensor can be further developed for large or small bend ranges measurement.
Deep learning as phase retrieval tool for CARS spectra
Authors: Houhou Rola , Barman Parijat , Schmitt Micheal , Meyer Tobias , Popp Juergen , Bocklitz Thomas
Published: April 2020

Finding efficient and reliable methods for the extraction of the phase in optical measurements is challenging and has been widely investigated. Although sophisticated optical settings, e.g. holography, measure directly the phase, the use of algorithmic methods has gained attention due to its efficiency, fast calculation and easy setup requirements. We investigated three phase retrieval methods: the maximum entropy technique (MEM), the Kramers-Kronig relation (KK), and for the first time deep learning using the Long Short-Term Memory network (LSTM). LSTM shows superior results for the phase retrieval problem of coherent anti-Stokes Raman spectra in comparison to MEM and KK.
Guiding and emission of milijoule single-cycle THz pulse from laser-driven wire-like targets
Authors: Zeng Yushan , Zhou Chuliang , Song Liwei , Lu Xiaoming , Li Zhongpeng , Ding Yingying , Bai Yafeng , Xu Yi , Leng Yuxin , Tian Ye , Liu Jiansheng , Li Ruxin , Xu Zhizhan
Published: April 2020

The miscellaneous applications of terahertz have called for an urgent demand of a super intense terahertz source. Here, we demonstrate the capability of femtosecond laser-driven wires as an efficient ultra-intense terahertz source using 700 mJ laser pulses. When focused onto a wire target, coherent THz generation took place in the miniaturized gyrotron-like undulator where emitted electrons move in the radial electric field spontaneously created on wire surface. The single-cycle terahertz pulse generated from the target is measured to be radially polarized with a pulse energy of a few milijoule. By further applying this scheme to a wire-tip target, we show the near field of the 500 nm radius apex could reach up to 90 GV/m. This efficient THz energy generation and intense THz electric field mark a substantial improvement toward ultra-intense terahertz sources.
Ambient light robust gamut mapping for optical see-through displays
Authors: Lee Kang-Kyu , Kim Jae-Woo , Ryu Je-Ho , Kim Jong-Ok
Published: April 2020

An optical see-through (OST) display is affected more severely by ambient light than any other type of displays when placed in an outdoor environment with bright illuminance because of its transparency and thus, its inherent color distortion can worsen. It is hard to directly apply existing gamut mapping methods to an OST display because of its morphological gamut characteristic and the effect of ambient light. In this paper, we propose a new robust gamut mapping method which works against bright ambient light. The process is divided into two steps: lightness mapping (LM) and chroma reproduction. LM aligns the lightness level of sRGB gamut with OST gamut and partitions the region of OST gamut based on the relative size of the sRGB gamut and its lightness value. The second step (chroma reproduction) determines an appropriate chroma reproduction method (gamut compression or extension) and a proper direction for gamut mapping based on the characteristics of each region in order to minimize the effects of ambient light. The quality of color reproduction is qualitatively and quantitatively evaluated based on accurate measurements of the displayed colors. It has been experimentally confirmed that the proposed gamut mapping method can reduce color distortion more than the existing parametric gamut mapping algorithms.
Compact ultrabroad-bandwidth cascaded arrayed waveguide gratings
Authors: van Wijk Arthur , Doerr Christopher R. , Ali Zain , Karabiyik Mustafa , Akca B. Imran
Published: April 2020

Here, we present a compact, high-resolution, and ultrabroad-bandwidth arrayed waveguide grating (AWG) realized in a silicon nitride (Si3N4) platform. The AWG has a cascaded configuration with a 1×3 flat-passband AWG as the primary filter and three 1×70 AWGs as secondary filters (i.e. 210 output channels in total). The primary AWG has 0.5-dB bandwidth of 45 nm over 190 nm spectral range. The ultrabroad-bandwidth is achieved by using an innovative design that is based on a multiple-input multi-mode interference (MMI) coupler placed at the entrance of the first free propagation region of the primary AWG. The optical bandwidth of the cascaded AWG is 190 nm, and the spectral resolution is 1 nm. The overall device size is only 1.1 × 1.0 cm2. Optical loss at the central channel is 4 dB, which is 3 dB less than a conventional design with the same bandwidth and resolution values but using a primary filter with Gaussian transfer function. To the best of our knowledge, this is the first demonstration of an ultrabroad-bandwidth cascaded AWG on a small footprint. We also propose a novel low-loss (∼ 0.8 dB) design using a small AWG instead of an MMI coupler in the primary filter part, which can be used in applications where the light intensity is very weak, such as Raman spectroscopy.
Stable high-energy, high-repetition-rate, frequency doubling in a large aperture temperature-controlled LBO at 515  nm
Authors: Phillips Jonathan P. , Banerjee Saumyabrata , Ertel Klaus , Mason Paul , Smith Jodie , Butcher Thomas , De Vido Mariastefania , Edwards Chris , Hernandez-Gomez Cristina , Collier John
Published: April 2020

We report on frequency doubling of high-energy, high-repetition-rate ns pulses from a cryogenically gas cooled, multi-slab Yb:YAG laser system, using a type-I phase–matched lithium triborate (LBO) crystal. Pulse energy of 4.3 J was extracted at 515 nm for a fundamental input of 5.4 J at 10 Hz (54 W), corresponding to a conversion efficiency of 77%. However, during long-term operation, a significant reduction of efficiency (more than 25%) was observed owing to the phase mismatch arising due to the temperature-dependent refractive index change in the crystal. This forced frequent angle tuning of the crystal to recover the second-harmonic generation (SHG) energy. More than a five-fold improvement in energy stability of SHG was observed when the LBO crystal was mounted in an oven, and its temperature was controlled at 27°C. Stable frequency doubling with 0.8% rms energy variation was achieved at a higher input power of 74 W when the LBO temperature was controlled at 50°C.
Ultra-broadband on-chip multimode power splitter with an arbitrary splitting ratio
Authors: Xu Hongnan , Dai Daoxin , Shi Yaocheng
Published: April 2020

The multimode power splitter is a basic component in mode-division multiplexing systems. In this paper, we propose an ultra-broadband silicon multimode power splitter enabling arbitrary power splitting ratios. The proposed multimode splitter is designed based on a waveguide crossing with an obliquely embedded subwavelength grating (SWG) transflector. The incident multiple guided-modes can be split into two beams with low excess losses and low crosstalk by the SWG transflector where the thin-film interference effect happens. As an example, a silicon multimode power splitter is designed to work with the three lowest-order modes of TE polarization. Any desired splitting ratio ranging from 0% to 100% can be achieved by engineering the structural parameters of the SWG. Moreover, the desired splitting ratio can be very uniform over an extremely broad bandwidth of ≥ 415 nm, covering O-, E-, S-, C-, L- and U-bands. The intermodal crosstalk is < −20 dB for all the input modes in theory. To the best of our knowledge, the proposed structure is the first multimode power splitter enabling any desired power splitting ratios in all the optical communication bands.
Participatory Action Research and design pedagogy: Perspectives for design education
Authors: Rowe Aidan
Published: April 2020

Design’s scope of practice has grown from one that was traditionally defined by materials and processes to one where designers are working on some of the most pressing challenges of our times. Once a reactive, artefact-based practice (e.g. poster, typeface, chair, etc.), design is now being situated as a proactive, social and participatory practice focused on outcomes as much as artefacts. Historically, as an academic subject, professional practice and research area, design has suffered from a lack of formal, established research frameworks and theoretical practices. By drawing on established literature, this article makes the case for the use of methods and practices developed in Participatory Action Research (PAR) to inform and enrich design practice, research and particularly education. The article identifies three shared areas between PAR and design that offer an opportunity for further interrogation; these are: a central concern of working with people; the use of iteration and reflection; and the measuring of success through change.
Foucauldian rituals of justice and conduct in Zainab Salbi’s Between Two Worlds
Authors: Pourya Asl Moussa
Published: April 2020

This article explores the Iraqi-American life writer Zainab Salbi’s memoir Between Two Worlds: Escape from Tyranny; Growing up in the Shadow of Saddam (2005) in the light of a Foucauldian framework to examine both visible and invisible tactics of power once exercised by Saddam Hussein’s authoritarian regime. The Foucauldian analysis of juridical forms and sovereign power as features of governmentality and political rationality are useful in understanding Salbi’s narration of Saddam Hussein’s use of the law and law-like regulations for perpetuating his authoritarian domination. I argue that through the ritual exercise of justice and conduct, the portrayed tyrant achieves the subjugation and constitution of individuals as well as the control of groups. The article suggests that by documenting her life story in an act of Foucauldian indocilité, or conscious insubordination, Salbi desubjugates the established politics of truth, and in so doing, detaches herself from the various modalities of subjectivity that the specific strategies of governmentality seek to formulate and impose on her as an Iraqi individual.
The German labour markets: the case for more flexibility
Authors: Rühmann Peter
Published: April 2020

A framework of different labour market segments is introduced to describe the stylised facts of the German labour market. Two processes, the outsourcing of production to Middle and Eastern Europe and the transfer of jobs to the shadow economy, are distinguished, which are eroding the formerly favourable labour market situation in Germany. It is argued that the shadow economy cannot operate as a substitute for the regular economy if the latter is put under strain and more flexibility is required. The framework used here seems to be in broad agreement with the stylised facts, showing that the process of adjustment has resulted mainly in changes to employment and the (official) GDP rather than to wages. Finally, the paper deals with the consequences that may arise if the recent emergence of selective wage concessions turns into a reduction in overall wage levels.
Abnormal returns in privatization public offerings: the case of Portuguese firms
Authors: Vieira Carla , Serra Ana Paula
Published: April 2020

This paper provides evidence on abnormal returns of Portuguese privatization public offerings for the period from 1989 to 2001. This study explores the abnormal performance of a comprehensive sample of Portuguese privatization transactions and investigates the determinants of the observed price behavior. We find some evidence of the underpricing phenomenon for privatized offerings but initial returns are low and barely significant. The results show further that privatization IPOs underperform private sector IPOs. In the long run, we observe negative abnormal returns. While in early event months, privatization public offerings yield more negative returns than private sector offerings, this effect is reversed in longer horizon periods. Initial underpricing is thus partially reversed and investors seem to require higher returns in partial privatizations.
Mobilidade geográfica e distância da deslocação em Portugal
Authors: Pereira João
Published: April 2020

Este artigo tem por objectivo analisar a mobilidade geográfica em Portugal tendo como domínio de referência a distância da deslocação. Tanto quanto é do nosso conhecimento, este é o primeiro trabalho que aborda esta questão em Portugal. A análise é efectuada com base num modelo logit multinomial. Os resultados obtidos mostram que há um conjunto de factores referenciados na literatura que influenciam a decisão individual de mobilidade nomeadamente, a idade, a situação familiar, as diferenças de salários e o desemprego. Contudo, dadas as estimativas que obtivemos para as probabilidades de deslocação, pode-se concluir claramente que este mecanismo está longe de ser uma forma eficaz de ajustamento do mercado de trabalho em Portugal. Neste sentido, são apontadas algumas vias de actuação da política económica que podem melhorar a eficácia deste mecanismo de ajustamento.
Healthy state, worried workers: North Carolina in the world economy
Authors: Gresser Edward
Published: April 2020

Healthy state, worried workers: North Carolina in the world economy
La Bienal de Arte de Venecia y la participación japonesa en su última década (2011-2019)
Authors: Cabañas Moreno Pilar
Published: April 2020

El objetivo de este artículo es valorar el carácter de las exposiciones artísticas como modo destacado de relación internacional entre gentes de distintos países. Centrarnos en realizar un análisis de la participación japonesa en las últimas cinco Bienales de Arte de Venecia nos ayudará, a través de sus planteamientos, a hilvanar un discurso que tiene mucho que ver con el ejercicio del soft power, de ahí el interés en profundizar en los planteamientos teóricos de cada una de ellas. A través del análisis, se demuestra una actitud proactiva de Japón para promover a nivel global y por medio de su experiencia, una corresponsabilidad en el repensar nuestra actitud soberbia frente a la naturaleza. El arte tiene mucho que decir en el mundo de la diplomacia.
Methodology of Problems Creation and Selection for Astronomy Olympiads on Example of Tasks on the Topic of Kepler's Laws
Authors: Ersteniuk Yaroslav , Gasyuk Ivan , Boryschak Anna , Yakubovskyi Petro
Published: April 2020

Based on many years of experience in the organization of the third stage of Ukrainian National Astronomy Olympiad, the authors of the article attempt to formulate general principles for the selection and compilation of astronomy olympiad problems, as well as to demonstrate the application of the described principles on the example of astronomy olympiads in Ivano-Frankivsk region. The peculiarities of school Olympiad in astronomy, the purpose of their conduct, the specificity of task packages, including necessity for differentiation by complexity and topics, were analyzed. A characteristic feature of the Olympiad tasks is their non-standard nature, necessity to use methods that are unusual for students to solve problems. On the other hand, such tasks should match intellectual development of the competition participants, and the course of the solution should be accessible to understanding and should not require knowledge of a university program. In particular, on the basis of the analysis by the authors of the process of compiling astronomy Olympiad tasks, which were offered to students in the past years at the regional stage of the student Olympiads, were identified, the methods of their creation were systematized and characterized. Each method contains a detailed explanation, justification for its use and examples, both analytical and practical. For the sake of clarity, the topic “Kepler Laws” was choosen for Olympiad problems, which were analyzed and methods used to create them were described. This topic is one of the fundamental in the schoolar astronomy, which determines both the need to include such tasks in the Olympiad program and the complexity of their choice, and creation, because the topic is narrow enough and is qualitatively covered in various textbooks and collections of problems.
Role of Psychological and Pedagogical Support in the Life of People With Disabilities?
Authors: Ziętek Аnna
Published: April 2020

The paper presents the essence and needs of support in the lives of people with disabilities. It shows that in order to adapt support to the individual needs of people with disabilities it is necessary to introduce elements improving the aid system. It indicates the tasks and importance of factors of the system supporting people with disabilities individually and in the social and professional environment. Legislative solutions in force were presented, which are aimed at stimulating professional activity and integrating disabled people and their families into the environment. The paper offers solutions to improve the system of equalization of opportunities in social and professional life of people with special needs. The importance of supporting professional activity and employment in the labour market was discussed. An attempt was made to assess the factors determining the effectiveness of the system, taking into account the implemented aid programs, grants, benefits and tasks of organizations and institutions supporting people with disabilities in social and professional life. The importance of integration, family support, support of the environment as well as adaptation of the system to the needs of people with disabilities was presented. Among the listed factors relating to people with disabilities, the importance of preparation, professional development and adaptation to the open labour market was presented. The social perception of disability is also of particular importance, which, if properly shaped, can reduce the problem of functioning of people with disabilities in social and professional life. People with disabilities show differing levels of need for safety, independence or accessibility to social infrastructure. This diversity depends on the support of families of people with disabilities, their caregivers and aid institutions and organizations, including those providing education, rehabilitation and vocational activity services. The paper presents activities, which are the starting point for looking for new solutions and improving current solutions for adapting support to the individual needs of people with disabilities
Quintín Lame, conciencia histórica y decreto autonómico. Rutas para la paz y la vida en Colombia
Authors: Molina Bedoya Víctor Alonso , Hurtado Cerón Arnulfo
Published: April 2020

El artículo analiza la relevancia que adquiere para los actuales momentos de diálogo social por la paz, el reconocimiento del carácter diverso de la sociedad colombiana. Condición que se expone en el tipo de relaciones sociales que definen el diario acontecer, que no es otra cosa, que la posibilidad que tienen los diferentes agrupamientos de construir sociedad a partir de sus formas de pensar, de ser y de estar en el territorio. En tal sentido, comprender los marcos normativos y la indigenidad son claves para valorar las posibilidades reales, tanto del decreto autonómico como de la autodeterminación indígena en Colombia