bluuebunny/crossref_metadata_2025 huggingface dataset:
3D constrained inversion of gravity and magnetic data to image basement and plutonic bodies: A case study from Dood Arale Basin, eastern Somaliland
Authors: Ali Mohammed Y. , Geng Meixia , Fairhead James Derek , Adan Ahmed
Published: July 2021

We have developed 3D inversion models derived from airborne gravity and magnetic data, which are constrained by seismic and well data, in eastern Somaliland. The density model reveals a northwest–southeast-trending basin, 125 km long and 25 km wide and called the Dood Arale Basin. The basin comprises two subbasins separated by a basement high and is infilled by up to 2500–3200 m of sediments. Smaller and shallower subbasins are also identified to the west of Lafaweyne and northeast of Dararweyne. The density model shows that the top basement in the platform areas is at approximately 1500–1700 m in depth and shallows to approximately 300 m at the Bur Anod, Hagraajin, and Hagrin Ranges and northwest of Eil Afwein. The basement depths in these areas are more uncertain and could be deeper because they occur in areas of high gravity anomalies caused by a combination of near-surface high-density sediments and high-density plutonic bodies within the basement. The susceptibility model indicates that the basement consists of very weakly magnetized metasediments of the Inda Ad Complex intruded by three northeast–southwest-trending magnetic bodies with upper surfaces at depths of approximately 300–3000 m. These magnetic bodies are interpreted as plutonic complexes of similar age and composition to the Lower Cretaceous syenite intrusions outcropping at Gorei in the Shilah Madu Range. Seismic reflection profiles image the sedimentary sequences, but they do not clearly map the top basement or detect any of the plutonic bodies. The plutonic bodies could have controlled the location of the basin’s border faults and contributed to the high geothermal gradient recorded at the Faro Hills-1 well. The Upper Cretaceous Gumburo and Jesomma Formations in the basin could potentially have reached maturation close to and above the plutonic bodies within the center of the basin.
Improving the hydrogeologic conceptualization of a remote semiarid palaeovalley groundwater system using airborne electromagnetics, seismic refraction and reflection, and downhole nuclear magnetic resonance
Authors: Flinchum Brady , Peeters Luk , Munday Tim , Cahill Kevin
Published: July 2021

A hydrogeologic conceptualization is critical to understand, manage, protect, and sustain groundwater resources, particularly in regions where data are sparse and accessibility is difficult. We used airborne electromagnetics (AEM), shallow seismic reflection and refraction, and downhole nuclear magnetic resonance (NMR) logs to improve our understanding of an arid groundwater system influenced by palaeovalleys. We found that there is a limited connection between the palaeovalley and fractured bedrock aquifers because they are separated by a spatially variable layer of saprolite, which is the layer of chemically altered rock on top of the fractured bedrock. The AEM data provided an estimate of the top of the saprolite but failed to effectively image the bottom. In contrast, the seismic data provided an estimate of the bottom of the saprolite but failed to image the top. This geophysical combination of electrical and seismic data allowed us to map saprolite thickness in detail along a 1.7 km long transect that runs perpendicular the main trunk of a well-defined palaeovalley. These data indicate that the palaeovalley is lined with a heterogeneous layer of saprolite (approximately 3–120 m thick) that is thickest near its edges. Despite the observed variability, only a small percentage of the fractured bedrock aquifer (8%–17%) appears to be in contact with the palaeovalley aquifer. Furthermore, the lack of an elastic boundary at the top of saprolite suggests that the porosity of the saprolite is similar to the palaeovalley sediments — an observation that is supported by the downhole NMR-derived water contents. The electrical change at the top of saprolite is caused by a combination of a decrease in total dissolved solids of the groundwater in the saprolite and a change in pore structure associated weathering in situ versus transported weathered materials. The presence of saprolite, which commonly behaves as an aquitard, may limit the groundwater exchange between the palaeovalley and bedrock aquifers, with implications for the regional groundwater resource potential.
Target-oriented inversion using the patched Green’s function method
Authors: da Silva Danyelle , Duarte Edwin Fagua , Almeida Wagner , Ferreira Mauro , Moura Francisco Alirio , de Araújo João Medeiros
Published: July 2021

We have designed a target-oriented methodology to perform full-waveform inversion (FWI) using a frequency-domain wave propagator based on the so-called patched Green’s function (PGF) technique. Originally developed in condensed matter physics to describe electronic waves in materials, the PGF technique is easily adaptable to the case of wave propagation in spatially variable media in general. By dividing the entire computational domain into two sections, namely the target area and the outside target area, we calculate the Green’s functions related to each section separately. The calculations related to the section outside the target are performed only once at the beginning of the inversion, whereas the calculations in the target area are performed repeatedly for each iteration of the inversion process. With the Green’s functions of the separate areas, we calculate the combined Green’s function of the two systems patched together through application of a recursive Dyson equation. The calculation is exact; that is, it is the same as the Green’s function calculated by directly solving the Helmholtz equation. By performing 2D and time-lapse experiments on the Marmousi and a Brazilian presalt velocity models, we determined that the target-oriented PGF reduces the computational time of the inversion without compromising accuracy. In fact, when compared with conventional FWI results, the PGF-based calculations are identical but done in a reduced time according to the target size.
Internal multiple prediction using inverse-scattering series with sparsity promotion — Part 1: Background, analysis, and synthetic modeling
Authors: Aaker Ole Edvard , Ramírez Adriana Citlali , Sadikhov Emin
Published: July 2021

The presence of internal multiples in seismic data can lead to artifacts in subsurface images obtained by conventional migration algorithms. This problem can be ameliorated by removing multiples prior to migration, if they can be reliably estimated. Recent developments have renewed interest in the plane-wave domain formulations of the inverse-scattering series (ISS) internal multiple prediction algorithms. We have built on this by considering sparsity-promoting plane-wave transforms to minimize artifacts and in general improve the prediction output. Furthermore, we argue for the use of demigration procedures to enable multidimensional internal multiple prediction with migrated images, which also facilitate compliance with the strict data completeness requirements of the ISS algorithm. We assert that a combination of these two techniques, sparsity-promoting transforms and demigration, paves the way for a wider application to new and legacy data sets.
Management of the Axilla in Early-Stage Breast Cancer: Ontario Health (Cancer Care Ontario) and ASCO Guideline
Authors: Brackstone Muriel , Baldassarre Fulvia G. , Perera Francisco E. , Cil Tulin , Chavez Mac Gregor Mariana , Dayes Ian S. , Engel Jay , Horton Janet K. , King Tari A. , Kornecki Anat , George Ralph , SenGupta Sandip K. , Spears Patricia A. , Eisen Andrea F.
Published: July 2021

PURPOSE

To provide recommendations on the best strategies for the management and on the best timing and treatment (surgical and radiotherapeutic) of the axilla for patients with early-stage breast cancer.

METHODS

Ontario Health (Cancer Care Ontario) and ASCO convened a Working Group and Expert Panel to develop evidence-based recommendations informed by a systematic review of the literature.

RESULTS

This guideline endorsed two recommendations of the ASCO 2017 guideline for the use of sentinel lymph node biopsy in patients with early-stage breast cancer and expanded on that guideline with recommendations for radiotherapy interventions, timing of staging after neoadjuvant chemotherapy (NAC), and mapping modalities. Overall, the ASCO 2017 guideline, seven high-quality systematic reviews, 54 unique studies, and 65 corollary trials formed the evidentiary basis of this guideline.

RECOMMENDATIONS

Recommendations are issued for each of the objectives of this guideline: (1) To determine which patients with early-stage breast cancer require axillary staging, (2) to determine whether any further axillary treatment is indicated for women with early-stage breast cancer who did not receive NAC and are sentinel lymph node–negative at diagnosis, (3) to determine which axillary strategy is indicated for women with early-stage breast cancer who did not receive NAC and are pathologically sentinel lymph node–positive at diagnosis (after a clinically node-negative presentation), (4) to determine what axillary treatment is indicated and what the best timing of axillary treatment for women with early-stage breast cancer is when NAC is used, and (5) to determine which are the best methods for identifying sentinel nodes. Additional information is available at www.asco.org/breast-cancer-guidelines .
Changes in Serum Calcium and Treatment of Hypoparathyroidism During Pregnancy and Lactation: A Single-center Case Series
Authors: Wang Jia-Jia , Wang Ou , Wang Ya-Bing , Yang Jing , Song An , Jiang Yan , Li Mei , Xia Wei-Bo , Xing Xiao-Ping
Published: July 2021

Background

Hypoparathyroidism (hypo-PT) is rare, and studies on hypo-PT, especially during pregnancy and lactation, are limited.

Design and Setting

This was a retrospective study on a relatively large case series in a single center from mainland China.

Methods

A total of 19 patients with 25 pregnancies, diagnosed with hypo-PT before pregnancy, were enrolled. Data on clinical characteristics and treatment strategies at onset time and around pregnancy period were collected.

Results

During pregnancy, except for 2 patients with missing data, 5 patients with 6 pregnancies (6/23, 26.1%) experienced improved hypo-PT condition, defined as an increased serum calcium level; 4 patients with 4 pregnancies (4/23, 17.4%) experienced worsened hypo-PT condition, defined as a more than 0.2 mmol/L decline in the serum calcium level; and 3 patients with 3 pregnancies (3/23, 13.0%) remained in stable hypo-PT condition. The prevalence of adverse pregnancy outcomes was 30.4% (4/23 for preterm delivery; 3/23 for miscarriage). The serum calcium and 24-hour urine calcium levels significantly increased during lactation compared with pregnancy (2.57 ± 0.34 vs 1.99 ± 0.11 mmol/L, P < 0.001; 12.28 ± 5.41 vs 8.63 ± 3.22 mmol/L, P = 0.013), and 5 patients with 5 lactations (5/12, 41.7%) developed hypercalcemia in the first 2 months after delivery.

Conclusions

Female patients with hypo-PT had different changes in calcium homeostasis and a high prevalence of adverse outcomes during pregnancy. Thus, they should be monitored closely to maintain the optimal serum calcium level. Decreasing drug dosage during the lactation period should be considered to avoid hypercalcemia.
Children and Law in the Shadows: Legal Ideologies and Personal Strategies in Response to Parental Abductions in Japan
Authors: Alexy Allison
Published: July 2021

In contemporary Japan, police and law enforcement are often reluctant to assist in family conflicts. In practice, law enforcement and the family law system offer little assistance for people struggling with family conflicts in particular, following the logic that “law does not belong in families.” This article examines the informal, familial, financial, and social means people use to solve what might be called “family problems” when formal legal assistance is foreclosed. Operating as alternatives to the legal system, these strategies nevertheless are structured directly in response to the formal legal system, what it supports and allows. The article uses theorizations of legal consciousness, law's “shadows,” and “order without law” to compare strategies and reactions of Japanese citizens and foreigners engaging the legal system in Japan. It argues that the written and unwritten rules surrounding Japanese family law reward those who seek solutions outside of formal channels, thereby co-constructing the legal system as unable to solve family conflicts. Linking individual strategies with outcomes, it concludes that family members who expect less assistance from the formal legal system often end up winning more.
Transduction of rat and human adipose-tissue derived mesenchymal stromal cells by adeno-associated viral vector serotype DJ
Authors: Zubkova Ekaterina S. , Beloglazova Irina B. , Ratner Elizaveta I. , Dyikanov Daniyar T. , Dergilev Konstantin V. , Menshikov Mikhail Yu. , Parfyonova Yelena V.
Published: July 2021

Ex vivo, gene therapy is a powerful approach holding great promises for the treatment of both genetic and acquired diseases. Adeno-associated virus (AAV) vectors are a safe and efficient delivery system for modification of mesenchymal stem cells (MSC) that could maximize their therapeutic benefits. Assessment of MSC viability and functional activity after infection with new AAV serotypes is necessary, due to AAV tropism to specific cell types. We infected human and rat adipose-tissue MSC with hybrid AAV-DJ serotype vectors carrying GFP and SCF genes. GFP expression from AAV-DJ was about 1.5-fold superior to that observed with AAV-2 and lasted for at least 21 days as was evaluated by flow cytometry and fluorescence microscopy. AAV-DJ proves to be suitable for the infection of rat and human MSC with a similar efficiency. Infected MSC were still viable but showed a 25-30% growth-rate slowdown. Moreover, we found an increase of SERPINB2 mRNA expression in human MSC while expression of other oxidative stress markers and extracellular matrix proteins was not affected. These results suggest that there is a differential cellular response in MSC infected with AAV viral vectors, which should be taken into account as it can affect the expected outcome for the therapeutic application.
Building bridges between fields: bringing together development and homeostasis
Authors: Weterings Sonja D. C. , van Oostrom Marek J. , Sonnen Katharina F.
Published: July 2021

Despite striking parallels between the fields of developmental biology and adult tissue homeostasis, these are disconnected in contemporary research. Although development describes tissue generation and homeostasis describes tissue maintenance, it is the balance between stem cell proliferation and differentiation that coordinates both processes. Upstream signalling regulates this balance to achieve the required outcome at the population level. Both development and homeostasis require tight regulation of stem cells at the single-cell level and establishment of patterns at the tissue-wide level. Here, we emphasize that the general principles of embryonic development and tissue homeostasis are similar, and argue that interactions between these disciplines will be beneficial for both research fields.
Phosphorylation in the intrinsically disordered region of F-BAR protein Imp2 regulates its contractile ring recruitment
Authors: Willet Alaina H. , Igarashi Maya G. , Chen Jun-Song , Bhattacharjee Rahul , Ren Liping , Cullati Sierra N. , Elmore Zachary C. , Roberts-Galbraith Rachel H. , Johnson Alyssa E. , Beckley Janel R. , Gould Kathleen L.
Published: July 2021

The F-BAR protein Imp2 is an important contributor to cytokinesis in the fission yeast Schizosaccharomyces pombe. Because cell cycle-regulated phosphorylation of the central intrinsically disordered region (IDR) of the Imp2 paralog Cdc15 controls Cdc15 oligomerization state, localization and ability to bind protein partners, we investigated whether Imp2 is similarly phosphoregulated. We found that Imp2 is endogenously phosphorylated on 28 sites within its IDR, with the bulk of phosphorylation being constitutive. In vitro, the casein kinase 1 (CK1) isoforms Hhp1 and Hhp2 can phosphorylate 17 sites, and Cdk1 (also known as Cdc2) can phosphorylate the remaining 11 sites. Mutations that prevent Cdk1 phosphorylation result in precocious Imp2 recruitment to the cell division site, and mutations designed to mimic these phosphorylation events delay Imp2 accumulation at the contractile ring (CR). Mutations that eliminate CK1 phosphorylation sites allow CR sliding, and phosphomimetic substitutions at these sites reduce Imp2 protein levels and slow CR constriction. Thus, like Cdc15, the Imp2 IDR is phosphorylated at many sites by multiple kinases. In contrast to Cdc15, for which phosphorylation plays a major cell cycle regulatory role, Imp2 phosphorylation is primarily constitutive, with milder effects on localization and function.

This article has an associated First Person interview with the first author of the paper.
Characterization of lipoprotein lipase storage vesicles in 3T3-L1 adipocytes
Authors: Roberts Benjamin S. , Yang Chelsea Q. , Neher Saskia B.
Published: July 2021

Lipoprotein lipase (LPL) is a secreted triglyceride lipase involved in the clearance of very-low-density lipoproteins and chylomicrons from circulation. LPL is expressed primarily in adipose and muscle tissues and transported to the capillary lumen. LPL secretion is regulated by insulin in adipose tissue; however, few studies have examined the regulatory and trafficking steps involved in secretion. Here, we describe the intracellular localization and insulin-dependent trafficking of LPL in 3T3-L1 adipocytes. We compared LPL trafficking to the better characterized trafficking pathways taken by leptin and GLUT4 (also known as SLC2A4). We show that the LPL trafficking pathway shares some characteristics of these other pathways, but that LPL subcellular localization and trafficking are distinct from those of GLUT4 and leptin. LPL secretion occurs slowly in response to insulin and rapidly in response to the Ca2+ ionophore ionomycin. This regulated trafficking is dependent on Golgi protein kinase D and the ADP-ribosylation factor GTPase ARF1. Together, these data give support to a new trafficking pathway for soluble cargo that is active in adipocytes.

This article has an associated First Person interview with the first author of the paper.
The Solution Chemistry of Mixing States Probed via Fluctuations: a Direct Description of Inhomogeneity in Mixing
Authors: Nishikawa Keiko
Published: July 2021

Radial distribution functions are commonly used to represent the structures of solutions, which represent the probability of finding another atom in the shell at a distance r from the atom of interest. This method has been used to study the structures of many non-crystalline materials. However, the information gained in this method is microscopic, and is limited to the first or second nearest neighbors from the featured atom. The present author proposed a completely different method to describe the solution structure by expressing the inhomogeneity in distribution of atoms and molecules and in concentration as “density fluctuation” and “concentration fluctuation”, respectively; namely the structure of a solution is described in terms of the “mixing state” or “mixing scheme.” This paper introduces density fluctuation and concentration fluctuation, as well as Kirkwood-Buff Integrals. Fluctuations of solutions become more pronounced in the mesoscale region. The relationship with solution thermodynamics, which represents the macroscopic limit, is also discussed. The features and cautions of experiments to measure the fluctuations are described. Finally, as analytical examples, temperature and concentration dependences of mixing schemes for two solution systems with upper critical and lower critical solution temperatures are presented.
Cardiorespiratory Fitness Associates with Blood Pressure and Metabolic Health of Children—The Arkansas Active Kids Study
Authors: DIAZ EVA C. , WEBER JUDITH L. , ADAMS SEAN H. , YOUNG CATARINA G. , BAI SHASHA , BØRSHEIM ELISABET
Published: July 2021

Introduction

High blood pressure (HBP) in children causes preclinical damage to the heart and accelerates atherosclerosis. Current pharmacological treatments have limited ability to prevent end-organ damage, particularly that of the kidneys. A contrasting element between adult versus pediatric HPB treatment is the emphasis in adults on exercise regimens that target increments in cardiorespiratory fitness (CRF; peak oxygen consumption [V˙O2peak]). The aim of this study was to evaluate the association of CRF with blood pressure percentiles and blood pressure status in children with normal and excessive adiposity (NA vs EA). An exploratory aim was to measure associations of CRF with (a) other cardiovascular disease risk factors commonly found in children with HBP and (b) kidney function.

Methods

Children (n = 211) attended one study visit. CRF was measured using an incremental bike test and body composition by dual-energy x-ray absorptiometry. Fat-free mass (FFM) index was calculated as kilograms of FFM per square meter. Multiple logistic and linear regression analyses were used to model the probability of HBP and other variables of interest (plasma lipids, HOMA2-IR, alanine aminotransferase, and estimated glomerular filtration rate) against V˙O2peak.

Results

CRF interacted with adiposity status in predicting the probability of HBP. Each additional milliliter per minute per FFM index in V˙O2peak decreased the odds of HBP by 8% in the EA group only (odds ratio = 0.92, 95% confidence interval = 0.87–0.99). Systolic and diastolic blood pressure percentiles decreased, and estimated glomerular filtration rate increased with increasing CRF in both adiposity-level groups. HOMA2-IR and alanine aminotransferase decreased with increasing CRF in children with EA only.

Conclusions

Higher CRF associated with decreased probability of clinical HBP, lower insulin resistance, and improved liver function in children with EA. Yet blood pressure percentiles and kidney function improved with increasing CRF irrespective of adiposity status.
Characterization of a novel variant in the HR1 domain of MFN2 in a patient with ataxia, optic atrophy and sensorineural hearing loss
Authors: Sharma Govinda , Sabouny Rasha , Joel Matthew , Martens Kristina , Martino Davide , de Koning A.P. Jason , Pfeffer Gerald , Shutt Timothy E.
Published: July 2021

Background: Pathogenic variants in MFN2 cause Charcot-Marie-Tooth disease (CMT) type 2A (CMT2A) and are the leading cause of the axonal subtypes of CMT. CMT2A is characterized by predominantly distal motor weakness and muscle atrophy, with highly variable severity and onset age. Notably, some MFN2 variants can also lead to other phenotypes such as optic atrophy, hearing loss and lipodystrophy. Despite the clear link between MFN2 and CMT2A, our mechanistic understanding of how dysfunction of the MFN2 protein causes human disease pathologies remains incomplete. This lack of understanding is due in part to the multiple cellular roles of MFN2. Though initially characterized for its role in mediating mitochondrial fusion, MFN2 also plays important roles in mediating interactions between mitochondria and other organelles, such as the endoplasmic reticulum and lipid droplets. Additionally, MFN2 is also important for mitochondrial transport, mitochondrial autophagy, and has even been implicated in lipid transfer. Though over 100 pathogenic MFN2 variants have been described to date, only a few have been characterized functionally, and even then, often only for one or two functions.

Method: Several MFN2-mediated functions were characterized in fibroblast cells from a patient presenting with cerebellar ataxia, deafness, blindness, and diffuse cerebral and cerebellar atrophy, who harbours a novel homozygous MFN2 variant, D414V, which is found in a region of the HR1 domain of MFN2 where few pathogenic variants occur.

Results: We found evidence for impairment of several MFN2-mediated functions. Consistent with reduced mitochondrial fusion, patient fibroblasts exhibited more fragmented mitochondrial networks and had reduced mtDNA copy number. Additionally, patient fibroblasts had reduced oxygen consumption, fewer mitochondrial-ER contacts, and altered lipid droplets that displayed an unusual perinuclear distribution.

Conclusion: Overall, this work characterizes D414V as a novel variant in MFN2 and expands the phenotypic presentation of MFN2 variants to include cerebellar ataxia.
Case Report: Duodenoscopy diagnosis of a secondary aorto-duodenal fistula: A case report and review of literature.
Authors: Elloumi Hanen , Melek Ben Mrad , Ganzoui Imen , Ben Hamida Sonia , Triki Wissem , Mchirgui Ilhem , Ben Hmida Makrem , Derbel Bilel , Cheikh Imed
Published: July 2021

Secondary aorto-enteric fistula (SAEF) is a rare life-threatening complication occurring in patients with previous infrarenal aortic prosthetic reconstruction. The main symptom is a gastrointestinal bleeding. Its diagnosis is challenging due to the lack of a specific clinical signs. The failure of early diagnosis and treatment of this entity can lead to fatal issue. Actually, the abdominal computed tomography angiogram represents the principal exploration to confirm the diagnosis, but it is associated with a moderate specificity and sensibility. Duodenoscopy can highlight the communication between the duodenum and the prosthetic graft, but it is often inconclusive. We report in this manuscript a case of secondary aorto-enteric fistula revealed by occult gastrointestinal bleeding in an elderly patient who is admitted for severe anemia. The SAEF diagnosis was suspected by the computed tomography scan and confirmed by the duodenoscopy showing an exceptional image of Dacron graft protruding in the third duodenum lumen. Unfortunately, the patient died from cataclysmic shock before intervention. We overview also the rare previous published case reports concerning the endoscopic images of secondary aortoenteric fistula and we contrast our findings with those reported in the literature.
A new locality record and distribution of Caluromys derbianus in México
Authors: Pérez-Gracida Luis David , Serna-Lagunes Ricardo
Published: July 2021

En México, el tlacuachillo dorado (Caluromys derbianus) se considera un mamífero raro y amenazado que habita bosques tropicales.  En los últimos 10 años, su presencia se ha registrado en 14 localidades, por lo que un nuevo registro contribuye a describir aspectos de su distribución geográfica.  El objetivo del estudio fue registrar las características del atropellamiento de un ejemplar de C. derbianus y describir su área de distribución geográfica en México con base en registros históricos y actuales.  El día 27 de agosto de 2019 se registró una hembra adulta de C. derbianus atropellada en la localidad de Peñuela, municipio de Amatlán de Los Reyes, Veracruz, México, localidad que se caracteriza por ser un área semiurbana, con presencia de vegetación secundaria y un arroyo tributario del Río Blanco.  Este registro, poco habitual por la baja densidad poblacional de la especie, confirma su presencia en una localidad no conocida dentro de su área de distribución potencial y ayuda a entender el efecto de la perturbación y fragmentación del bosque tropical subperennifolio sobre el hábitat de esta especie.
Automatic Fault Diagnosis Method for Hydrodynamic Control System
Authors: Zheng Jin
Published: July 2021

In order to improve the accuracy and speed of fault data acquisition of fluid power control system, this paper designs an automatic fault diagnosis method of fluid power control system based on English translation speech recognition. Firstly, the SDG model of the fluid dynamic control system is established, and the fault link is obtained and determined. Then the correlation dimension of data in fluid mechanics calculation is analyzed, and the fault data location is realized. On this basis, the fault classification model of the hydraulic power control system is established, and the automatic fault diagnosis of the hydraulic power control system is completed. Experiments show that the new fault diagnosis method can effectively improve the accuracy and speed of fault data acquisition of fluid power control system, the highest accuracy can reach 89.92%, the fastest speed is 11s, and improve the reliability of fault diagnosis results.
Institutional logics as a framework for understanding third sector development: an analysis of Quebec and Scotland
Authors: McMullin Caitlin , Roy Michael J. , Curtin Maeve
Published: July 2021

We compare the development of the third sector in Scotland and Quebec, which have developed ecosystems that distinguish them from the liberal non-profit regimes of the UK and Canada. We employ an institutional logics framework to consider how the rules, practices, values and beliefs of these ‘stateless nations’ have formed unique structures and identities of the third sector that diverge from their broader national context. Our model demonstrates how the development of the welfare state and approaches to implementing social policy, government–third sector relationships, civic nationalism and solidarity interact in an iterative process to create distinct third sectors.
Gendered path dependency: women’s representation in 20th-century Brazil
Authors: dos Santos Pedro A.G.
Published: July 2021

This study investigates women’s under-representation in national legislative elections and the gendered legacies embedded in Brazil’s electoral system and party dynamics. Focusing on the historical period prior to the 1996 implementation of a quota law, this article applies a feminist historical institutionalist approach to identify institutions and actors influencing women’s representation. Brazil’s electoral rules for legislative elections, that is, an open-list proportional representation system, remained surprisingly stable throughout periods of regime change and institutional uncertainty in the 20th century. It was not until the return to democracy and the 1986 constituent election that women were able to carve some space in Brazil’s National Congress. This research argues that the relaxing of rules dictating the creation of political parties and the strengthening of women’s movements in the prior decade were influential in creating a propitious moment for increasing the presence of women in national legislative politics.
Tunable liquid crystal asymmetric dual-core photonic crystal fiber mode converter
Authors: Mohsen H. Mahmoud Mohamed , Younis B. M. , Areed Nihal F. F. , Hameed Mohamed Farhat O. , Obayya S. S. A.
Published: July 2021

In this study, a compact mode converter based on an asymmetric dual-core photonic crystal fiber (ADC-PCF) infiltrated with nematic liquid crystal (NLC) is reported. The full vectorial finite difference method is used to compute the modal characteristics of the studied transverse magnetic (TM) mode. In this investigation, the geometrical and material parameters of the proposed mode converter are studied to achieve high wavelength selectivity with a compact device length. The proposed mode converter has a compact device length of 403.6 µm at

λ
=

1.3

µ

m

. In addition, the reported device is simulated under different temperature levels from 15°C to 45°C to show the thermal tunability. Therefore, the proposed design can be used efficiently in integrated photonic circuits.
Au nanoparticle concentration study in hybrid plasmonic microlasers
Authors: Manzo Maurizio
Published: July 2021

In this paper, the concentration effects of Au nanoparticles placed in dye-doped polymeric spherical microlasers are investigated. The microlasers (average diameter of

∼

293

µ

m

) are made with a mixture of UV curable polymer named Norland Blocking Adhesive (NBA) and Rhodamine 6 G. Four different ratios (between the Au nanoparticles and the NBA solutions) are investigated here, namely, 1000, 2000, 3000, and 4000 ratios. The Au nanoparticles (size of

∼

5

n
m

) are randomly scattered within the microlaser. The light is collected via a multimode optical fiber, ending to a spectrometer/CCD camera. It is found that the 3000 ratio case exhibited the lowest energy threshold value and the highest photonic emission slope. The 4000 ratio (lowest concentration) exhibited a behavior that was very similar to a microlasers with no Au particles. In terms of longevity of the laser modes, the 3000 ratio case exhibited the most stable emission, although the laser mode disappeared at an earlier time. The emission of the 2000 ratio case dropped drastically after a few seconds but increased after that before dropping again; in this case, the TE and TM laser modes were found to be in competition with each other due to the partial overlapping of the plasmonic emission with some of the resonant cavity modes and due to the thermal expansion effect. The quality factor was found to be of the same order of magnitude for all cases (

∼

10
4

). Ultimately, this work allows us to select the optimum microlaser’s configuration in terms of Au nanoparticle concentration as well as laser mode emission and longevity for different mechanical and biomedical sensing applications.
Demonstration of Yb3+-doped and Er3+/Yb3+-codoped on-chip microsphere lasers
Authors: Hu Yun-Qi , Mao Xuan , Yang Hong , Wang Min , Qin Guo-Qing , Long Gui-Lu
Published: July 2021

Rare-earth-doped on-chip microlasers are of great significance in both fundamental research and engineering. To the best of our knowledge, this is the first report of Yb3+-doped and Er3+/Yb3+-codoped on-chip microsphere lasers fabricated via sol-gel synthesis. Laser emissions were observed in a band around 1040 nm in both Yb3+-doped and Er3+/Yb3+-codoped resonators pumped at 980 nm and had measured ultralow thresholds of 5.2 µW and 0.6 µW, respectively. Both single-mode and multi-mode emissions were recorded around 1040 nm in these lasers. Single-mode and two-mode emissions were obtained at 1550 nm in the Er3+/Yb3+-codoped lasers when pumped at 980 nm and 1460 nm, respectively. Furthermore, quality factors induced by different loss mechanisms in the microsphere lasers are theoretically estimated. These resonators are expected to contribute to the high-density integration of on-chip silica-based microlasers.
Magnon-mediated nonreciprocal microwave transmission based on quantum interference
Authors: Kong Cui , Bao Xi-Min , Liu Ji-Bing , Xiong Hao
Published: July 2021

Nonreciprocity has always been a subject of interest and plays a key role in a variety of applications like signal processing and noise isolation. In this work, we propose a simple and feasible scheme to implement nonreciprocal microwave transmission in a high-quality-factor superconducting cavity with ferrimagnetic materials. We derive necessary requirements to create nonreciprocity in our system where a magnon mode and two microwave modes are coupled to each other, highlighting the adjustability of a static magnetic field controlled nonreciprocal transmission based on quantum interference between different transmission paths, which breaks time-reversal symmetry of the three-mode cavity magnonics system. The high light isolation adjusted within a range of different magnetic fields can be obtained by modulating the photon-magnon coupling strength. Due to the simplicity of the device and the system tunability, our results may facilitate potential applications for light magnetic sensing and coherent information processing.
Bifocal focusing and polarization demultiplexing by a guided wave-driven metasurface
Authors: Xie Chenkai , Huang Lirong , Liu Wenbing , Hong Wei , Ding Jifei , Wu Wei , Guo Min
Published: July 2021

Metasurfaces have shown extraordinary light-manipulation abilities, however, most of them deal with free-space waves. It is highly desirable to develop a guided wave-driven metasurface which can extract the in-plane guided modes in the waveguide and mold it into the desired out-of-plane free-space modes. In this paper, an all-dielectric guided wave-driven metasurface, composed of an array of silicon meta-atoms on top of a silicon nitride waveguide, is proposed and simulatively demonstrated. When directly driven by fundamental transverse electric (TE00) and fundamental transverse magnetic (TM00) guided modes at operation wavelength 1.55 µm, the guided wave-driven metasurface converts them into y-polarized and x-polarized free-space light, respectively, and focuses them at different focal points, with polarization extinction ratio over 27 dB, thus simultaneously realizing triple functions of coupling guided modes to free-space waves, bifocal metalens and polarization demultiplexing. Our work offers an alternate way to control light across photonic integrated devices and free-space platforms.
Terahertz vortex beam generator based on bound states in the continuum
Authors: Bai TaiRong , Li Qian , Wang YiQing , Chen YiFan , Hu Zheng-Da , Wang Jicheng
Published: July 2021

Vortex beams are playing an increasingly crucial role in wireless optical communications. Traditional vortex beam generators based on spiral phase plates and metasurfaces have a geometric center in real space, which limit their convenience in practical applications. In this work, we propose that the creation of a vortex beam can be achieved by using the bound state in the continuum (BIC) supported by a photonic crystal slab structure. Theoretical analysis shows that the proposed structure can be used as a kind of “momentum-space resonators” and thus can generate vortex beams. Moreover, higher-order vortex beams can also be achieved by changing the symmetry of photonic crystal slab, thus paving the way for the application of vortex beams in the fields of quantum information processing and micro optical micromanipulation.
Velocity measurement of an arbitrary three-dimensional moving object by using a novel modulated field
Authors: Zhong Yiming , Zhang Yi , Zhang Xiangdong , Sun Houjun , Zhao Guoqiang
Published: July 2021

The rotational Doppler effect caused by vortex beam carrying orbital angular momentum is recently used to estimate the rotational velocity of the object. However, the vortex beam only has the spiral phase distribution in one dimension, which means that only the rotational movement of the object would introduce the frequency shift. Also, the vortex beam has a spatial amplitude distribution of doughnut-shaped, which is not suitable for many application scenarios. To simultaneously measure the velocity of an arbitrary three-dimensional moving object, we propose theoretically and demonstrate experimentally an effective method by constructing a novel modulated field. Different from the plane wave and the vortex beam, the modulated field has linear phase distribution in azimuth and elevation directions. In addition, the modulated field has the maximal radiation intensity in the center, which avoids the beam divergence of the vortex beam. By decomposing the frequency shift caused by the radial, azimuth and elevation movements, we realize the velocity measurement in three dimensions. Experiments in a microwave system show that the estimated velocity errors are lower than 6.0%.
Efficient calculation of highly focused electromagnetic Schell-model beams
Authors: Aviñoá Marcos , Martínez-Herrero Rosario , Carnicer Artur
Published: July 2021

The calculation of the propagation of partially coherent and partially polarized optical beams involves using 4D Fourier Transforms. This poses a major drawback, taking into account memory and computational capabilities of nowadays computers. In this paper we propose an efficient calculation procedure for retrieving the irradiance of electromagnetic Schell-model highly focused beams. We take advantage of the separability of such beams to compute the cross-spectral density matrix by using only 2D Fourier Transforms. In particular, the number of operations depends only on the number of pixels of the input beam, independently on the coherence properties. To provide more insight, we analyze the behavior of a beam without a known analytical solution. Finally, the numerical complexity and computation time is analyzed and compared with some other algorithms.
Efficient Bloch mode calculation of periodic systems with arbitrary geometry and open boundary conditions in the complex wavevector domain
Authors: Kamandar Dezfouli Mohsen , Melati Daniele , Grinberg Yuri , Al-Digeil Muhammad , Cheriton Ross , Cheben Pavel , Schmid Jens H. , Janz Siegfried , Xu Dan-Xia
Published: July 2021

We show how existing iterative methods can be used to efficiently and accurately calculate Bloch periodic solutions of Maxwell’s equations in arbitrary geometries. This is carried out in the complex-wavevector domain using a commercial frequency-domain finite-element solver that is available to the general user. The method is capable of dealing with leaky Bloch mode solutions, and is extremely efficient even for 3D geometries with non-trivial material distributions. We perform independent finite-difference time-domain simulations of Maxwell’s equations to confirm our results. This comparison demonstrates that the iterative mode finder is more accurate, since it provides the true solutions in the complex-wavevector domain and removes the need for additional signal processing and fitting. Due to its efficiency, generality and reliability, this technique is well suited for complex and novel design tasks in integrated photonics, and also for a wider range of photonics problems.
Localization-to-delocalization transition of light in frequency-tuned photonic moiré lattices
Authors: Zeng Jiongchao , Hu Yanwen , Zhang Xin , Fu Shenhe , Yin Hao , Li Zhen , Chen Zhenqiang
Published: July 2021

We demonstrate in a numerical manner the intriguing localization-to-delocalization transition of light in frequency-tuned photonic moiré lattices, both in the zero-order and the higher-order regimes of light waves. We present a different technique to realize the composite photonic lattices, by means of two relatively twisted sublattices with different modulated lattice constants. Even though various kinds of photonic patterns including the commensurable and the incommensurable lattices can be well constructed, the observed transition between the localization and the delocalization of light field is moiré angle-independent. This angle-insensitive property was not reported before, and cannot be achieved by those photonic moiré lattices that are all moiré angle-dependent. We reveal that the obtained phase transition of light is robust to the changes of refractive index modulation of the photonic lattices. Moreover, we reveal that the effect of moiré angle-independent transition of light can be extended to the higher-order vortex light field, hence allowing prediction, for the first time to our knowledge, of both the localization and the delocalization of the vortex light field in the photonic lattices.
Highly precise in-plane displacement sensor based on an asymmetric fiber Fabry–Perot interferometer
Authors: Wang Zihao , Xu Zhilin , Chen Liuyang , Shi Yi , Wang Xiaoyun , Wu Junhui , Fan Ji , Tu Liangcheng
Published: July 2021

An in-plane displacement sensor based on an asymmetric extrinsic fiber Fabry–Perot interferometer (EFPI) is proposed and demonstrated. The asymmetric EFPI composed of a step-shaped external reflector and a cleaved fiber end face can be equivalent to two parallel FPIs with slightly different cavity lengths. By calculating the peak intensity difference of the two FPIs, the in-plane displacement can be demodulated with enhanced sensitivity and suppressed common mode noise. Both theoretical analyses and experimental results show that the sensitivity and the linear range of the in-plane displacement sensor are dependent on the cavity length. A displacement resolution of 5 nm and a linear range of

±

7

µ

m

under the cavity length of 250 µm are achieved in the experiment. The proposed in-plane displacement sensor with a nanometric resolution and compact size can be widely used in the fields of metrology, accelerometers, and semiconductor manufacture.
Ultrahigh-definition volumetric light field projection
Authors: Jo Youngjin , Bang Kiseung , Yoo Dongheon , Lee Byounghyo , Lee Byoungho
Published: July 2021

We introduce a projection-type light field display featuring effective light modulation. By combining a tomographic display with integral imaging (InIm) technology, a novel optical design is capable of an autostereoscopic light field projector. Here, the tomographic approach generates a high-resolution volumetric scene, and InIm makes it possible for the volumetric scene to be reconstructed on a large screen through a projection. Since all the processes are realized optically without digital processing, our system can overcome the performance limitations associated with the number of pixels in the conventional InIm displays. We built a prototype display and demonstrated that our optical design has the potential of massive resolution with a full-parallax in a single device.
Time-resolved dual-comb spectroscopy with a single electro-optic modulator
Authors: Huh Jeong Hyun , Chen Zaijun , Vicentini Edoardo , Hänsch Theodor W. , Picqué Nathalie
Published: July 2021

Time-resolved near-infrared absorption spectroscopy of single non-repeatable transient events is performed at high spectral resolution with a dual-comb interferometer using a continuous-wave laser followed by a single electro-optic amplitude modulator. By sharing high-speed electrical/optical components, our spectrometer greatly simplifies the implementation of dual-comb spectroscopy and offers a high mutual coherence time, measured up to 50 s, without any active stabilization system and/or data processing. The time resolution is as short as 100 µs in our experimental demonstration. For a span of 36 GHz, the mean signal-to-noise ratio of 80, at 100-MHz spectral resolution and 100-µs measurement time, enables precise determination of the parameters of rovibrational lines, including intensity or concentration.