bluuebunny/crossref_metadata_2025 huggingface dataset:
Health insurance enrollment strategies during the Affordable Care Act (ACA): a scoping review on what worked and for whom
Authors: Ercia Angelo , Le Nga , Wu Runguo
Published: July 2021

Background

The Affordable Care Act (ACA) provided an opportunity for millions of people in the U.S. to get coverage from the publicly funded Medicaid program or private insurance from the newly established marketplace. However, enrolling millions of people for health insurance was an enormous task. The aim of this review was to examine the strategies used to enroll people for health insurance and their effectiveness after implementing the ACA’s coverage expansion.

Methods

The PRISMA Extension for Scoping Review (PRISMA-ScR) guided this review. Included studies were empirical studies that met the inclusion criteria and published between 2010 and 2020. Studies were searched mainly from two scholarly databases, CINAHL Plus and Medline (PubMed) using keyword searches. Hand searches from the references of selected journals were also performed. Content analysis was conducted by two authors in which codes were inductively developed to identify themes.

Results

There were 2213 potential studies identified from the search, but 10 met the inclusion criteria. The research design of the studies varied. Two studies were randomized trials, one quasi-experimental trial, three mixed-methods, two qualitative and two quantitative. All studies focused on strategies used to inform and help people enroll for either Medicaid or private insurance from the marketplace. This review identified three key strategies used to help enroll people for coverage: 1) individual assistance; 2) community outreach; and 3) health education and promotion (HE&P).

Conclusion

Community-based organizations were likely to use a combination of the three strategies simultaneously to reach uninsured individuals and directly help them enroll for health insurance. Other organizations that aimed to reach a wider segment of the population used single strategies, such as community outreach or HE&P.
Depression remains a neglected public health problem among pregnant women in Northwest Ethiopia
Authors: Beyene Getnet Mihretie , Azale Telake , Gelaye Kassahun Alemu , Ayele Tadesse Awoke
Published: July 2021

Background

Antenatal depression is highly prevalent but a neglected public health problem in low income countries. It has serious effects on the general health of women, birth outcomes and child health. However, there has been limited substantial evidence on the prevalence and predictors of antenatal depression in Ethiopia. This lack of evidence potentiates the consequences of the problem and can limit the attention to intervention. Thus, this study aimed to assess the prevalence and potential predictors of antenatal depression at Debre Tabor and Woreta towns, Northeast Ethiopia.

Methods

A community-based cross-sectional study was employed on 548 pregnant women recruited by a cluster sampling method. Depressive symptoms were measured using the Edinburgh Postnatal Depression Scale (EPDS). The List of Threatening Experiences Questionnaire (LTE-Q), the Oslo-3 Social Support Scale (OSSS-3), Intimate Partner Violence (IPV) Scale and Fast Alcohol Screening Test (FAST) were also used to measure stressful events, social support, intimate partner violence (IPV) and hazardous alcohol use respectively. Bivariable and multivariable logistic regression analyses were carried out to identify factors associated with antenatal depression.

Results

The prevalence of antenatal depression was found to be 24.45% (95% CI: 21.20, 28.30%). Being single (AOR =3.32, 95% CI = 1.36, 8.09); fear of pregnancy complication (AOR = 3.84, 95% CI = 1.53,9.62); history of chronic illness (AOR = 8.14, 95% CI = 2.14, 30.91); unplanned pregnancy (AOR = 2.99, 95% CI = 1.36,6.55); history of stillbirth (AOR = 3.56, 95% CI = 1.23, 10.29),one or more negative life events (AOR = 4.06, 95% CI = 1.71, 9.66) and intimate partner violence (AOR = 3.91, 95% CI = 1.65, 9.26) were factors significantly associated with antenatal depression.

Conclusion

Nearly a quarter of pregnant women suffer from depressive symptoms during pregnancy. Being single; fear of pregnancy complication; history of chronic illness; unplanned pregnancy; history of stillbirth; one or more negative life events and intimate partner violence were important predictors of antenatal depression in this study. Health care workers should consider addressing these risk factors during a routine antenatal care. Also, integrating early screening, detection, and treatment of antenatal depression into routine antenatal care is warranted to improve the quality of life of pregnant women and pregnancy outcomes as well.
Linking qualitative scenarios with quantitative energy models: knowledge integration in different methodological designs
Authors: Prehofer Sigrid , Kosow Hannah , Naegler Tobias , Pregger Thomas , Vögele Stefan , Weimer-Jehle Wolfgang
Published: July 2021

Background

Linking qualitative scenarios with quantitative models is a common approach to integrate assumptions on possible future societal contexts into modeling. But reflection on how and to what degree knowledge is effectively integrated during this endeavor does not generally take place. In this paper, we reflect on the performance of a specific hybrid scenario approach (qualitative Cross-Impact Balance analysis, CIB, linked with quantitative energy models) concerning knowledge integration through 11 different process steps. In order to guide the scenario community in applying this approach, we reflect on general methodological features as well as different design options. We conceptualize different forms of interdisciplinary knowledge integration (compiling, combining and synthesizing) and analyze how and to what degree knowledge about society and uncertainty are integrated into scenario process and products. In addition, we discuss trade-offs regarding design choices and forms of knowledge integration.

Results

On the basis of three case studies, we identify two general designs of linking which build on each other (basic and extended design) and which differ in essence regarding the balance of power between the CIB and the energy modeling. Ex post assessment of the form of interdisciplinary knowledge integration in each step revealed that specific method properties of CIB as well as the interaction with additional quantitative as well as specific qualitative methods foster distinct forms of knowledge integration. The specific roles assigned to CIB in the hybrid scenario process can also influence the form of knowledge integration.

Conclusions

In this study, we use a joint process scheme linking qualitative context scenarios with energy modeling. By applying our conceptualization of different forms of knowledge integration we analyze the designs’ respective potential for and respective effects on knowledge integration. Consequently, our findings can give guidance to those who are designing their own hybrid scenario processes. As this is an explorative study, it would be useful to further test our hypotheses in different hybrid scenario designs. Finally, we note that at some points in the process a more precise differentiation of three forms of knowledge integration would have been useful and propose to further differentiate and detail them in future research.
Trends and dynamics of material and energy flows in an urban context: a case study of a city with an emerging economy
Authors: Pardo Martínez Clara Inés , Alfonso Piña William , Facchini Angelo , Cotte Poveda Alexander
Published: July 2021

Background

Currently, most of the world’s population lives in cities, and the rapid urbanization of the population is driving increases in the demand for products, goods and services. To effectively design policies for urban sustainability, it is important to understand the trends of flows in energy and materials as they enter and leave a city. This knowledge is essential for determining the key elements characterizing future urban growth and addressing future supply challenges.

Methods

This paper presents an analysis of the energy and material flows in the city of Bogotá over the time span from 2001 to 2017. Urban flows are also characterized in terms of their temporal evolution with respect to population growth to compare and identify the changes in the main input flows, wealth production, emissions and waste in the city.

Results

The results of the analysis are then compared with those for other selected large urban agglomerations in Latin America and worldwide to highlight similarities and make inferences. The results show that in Bogotá, there was a decrease in some of the material flows, such as the consumption of water and the generation of discharge, in recent years, while there was an increase in the consumption of energy and cement and in the production of CO2 emissions and construction materials. Solid waste production remained relatively stable. With respect to the other large cities considered, we observe that the 10-year growth rates of the flows with respect to population growth are lower in Bogotá, particularly when compared with the other urban agglomerations in Latin America.

Conclusions

The findings of this study are important for advancing characterizations of the trends of material and energy flows in cities, and they contribute to the establishment of a benchmark that allows for the definition and evaluation of the different impacts of public policy while promoting the sustainability of Bogotá in the coming decades.
International trade barriers and regional employment: the case of a no-deal Brexit
Authors: Brautzsch Hans-Ulrich , Holtemöller Oliver
Published: July 2021

We use the World Input–Output Database (WIOD) combined with regional sectoral employment data to estimate the potential regional employment effects of international trade barriers. We study the case of a no-deal Brexit in which imports to the United Kingdom (UK) from the European Union (EU) would be subject to tariffs and non-tariff trade costs. First, we derive the decline in UK final goods imports from the EU from industry-specific international trade elasticities, tariffs and non-tariff trade costs. Using input–output analysis, we estimate the potential output and employment effects for 56 industries and 43 countries on the national level. The absolute effects would be largest in big EU countries which have close trade relationships with the UK, such as Germany and France. However, there would also be large countries outside the EU which would be heavily affected via global value chains, such as China, for example. The relative effects (in percent of total employment) would be largest in Ireland followed by Belgium. In a second step, we split up the national effects on the NUTS-2 level for EU member states and additionally on the county (NUTS-3) level for Germany. The share of affected workers varies between 0.03% and 3.4% among European NUTS-2 regions and between 0.15% and 0.4% among German counties. A general result is that indirect effects via global value chains, i.e., trade in intermediate inputs, are more important than direct effects via final demand.
Test review of Iranian university entrance exam: English Konkur examination
Authors: Khodi Ali , Alavi Sayyed Mohammad , Karami Hossein
Published: July 2021

The present paper appraises a standardized test, the entrance exam of Iranian universities, known as “Konkur” that is administered annually as a means of gaining admission to higher education in Iran. This norm-referenced test is administered for students majoring in mathematics, experimental sciences, and humanities whose scores along their weighted GPAs in the last 3 years of high school are used as indicators of students’ rank. Based on the rank achieved, they would find the opportunity to select the highly regarded university for their education. Due to the importance of such a high-stake test which may bring about social and long-time consequences for the participants, the present paper tries to evaluate the test and its psychometrics aspects. It is ostensible that the exam provides a limited  situation for measuring the participants “knowledge of language” rather than their “knowledge about language.” Therefore, the dimensionality and validity of the test are debatable. Thus, the present review tries to characterize Konkur examination and discusses the rooms for untouched aspects for the betterment of its quality.
Assessing the treatment of cannabidiolic acid methyl ester: a stable synthetic analogue of cannabidiolic acid on c-Fos and NeuN expression in the hypothalamus of rats
Authors: Murillo-Rodríguez Eric , Millán-Aldaco Diana , Arankowsky-Sandoval Gloria , Yamamoto Tetsuya , Pertwee Roger G. , Parker Linda , Mechoulam Raphael
Published: July 2021

Background

Cannabidiol (CBD), the non-psychotropic compound from Cannabis sativa, shows positive results on controlling several health disturbances; however, comparable data regarding additional chemical from C. sativa, such as cannabidiolic acid (CBDA), is scarce due to its instability. To address this limitation, a stable CBDA analogue, CBDA methyl ester (HU-580), was synthetized and showed CBDA-like effects. Recently, we described that HU-580 increased wakefulness and wake-related neurochemicals.

Objective

To extend the comprehension of HU-580´s properties on waking, the c-Fos and NeuN expression in a wake-linked brain area, the hypothalamus was evaluated.

Methods

c-Fos and NeuN expression in hypothalamic sections were analyzed after the injections of HU-580 (0.1 or 100 μg/kg, i.p.).

Results

Systemic administrations of HU-580 increased c-Fos and neuronal nuclei (NeuN) expression in hypothalamic nuclei, including the dorsomedial hypothalamic nucleus dorsal part, dorsomedial hypothalamic nucleus compact part, and dorsomedial hypothalamic nucleus ventral part.

Conclusion

HU-580 increased c-Fos and NeuN immunoreactivity in hypothalamus nuclei suggesting that this drug might modulate the sleep–wake cycle by engaging the hypothalamus.
Specialist teams as constituted are unsatisfactory for treating people with personality disorders
Authors: Duggan Conor , Tyrer Peter
Published: July 2021

It is now becoming standard practice in most advanced economies to provide specialist services for those with personality disorder. Such services, almost exclusively, provide complex well-structured psychological interventions lasting many months for a small number of those with borderline personality disorder pathology. The evidence suggests that these treatments are effective but they can only be provided for a small number of people. However, in every area the numbers of patients with significant personality disorder far exceeds those that are treated, and most of these have other personality disorders. It is argued that the current service system is not working efficiently and should be replaced by one that provides resources and expertise within community teams with some external advice from specialists but no transfer of responsibility to a designated team.
“To Conclude on a General Union” Masculinity, the Chickamauga, and Pan-Indian Alliances in the Revolutionary Era
Authors: Mize Jamie Myers
Published: July 2021

Utilizing gender as a lens for understanding the political decisions of Cherokee men in the Revolutionary era, this article examines the evolution of Cherokee manhood as Cherokee men renegotiated their masculinity in the wake of colonial pressures. A group known as the Chickamauga sought to maintain historic expressions of manhood and developed several strategies to do so. In particular, Chickamauga men worked tirelessly to establish pan-Indian alliances and to unite military efforts against American settlers. Amid these efforts, the warrior-diplomat emerged as a masculine ideal in Cherokee society.
Helical Homometallic Trinickel String Complexes with Mixed Hard Nitrogen and Sulfur Donors: Structural and Magnetic Studies
Authors: Cheng Ming-Chuan , Cheng Chien-Hung , Chen Po-Jung , Lin Tien-Sung , Lee Gene-Hsiang , Liu Yu-Chiao , Chiang Ming-Hsi , Peng Shie-Ming
Published: July 2021

A new tridentate and rigid ligand containing S,N-hetero donor, the 1H-1,8-naphthyridine-2-thione (Hnpt), is designed and developed to build up the first homonuclear nickel string supported by the mixed-donor ligands. Three asymmetric nickel strings possessing the structural feature of the (4,0) configuration are synthesized, namely the (4,0)-Ni3(npt)4(NCS) (1), (4,0)-[Ni3(npt)4(NCS)](PF6) (2) and (4,0)-Ni3(npt)4(NCS)2 (3). Due to the nature of the naphthyridyl group and sulfur donor, complex 1 is composed of one stabilized mixed-valent unit [Ni2]3+ and one low spin nickel thiolate. 1 and 2 are the quasi-1D coordination polymers in the solid-state, in which the molecules are linked by the weak intermolecular Ni⋯SCN interactions. 2 and 3 possess the same Ni36+ oxidized state with the different donation of axial ligands. The weaker donor in 2 yields the low spin state in the middle Ni(II). The stronger axial donor and the rigidity of ligand in 3 lead to the change of torsion angle, creating the unprecedented high spin Ni(II) inside the nickel string. This high spin Ni(II) with the square planar geometry is an unusual structure and magnetism among nickel strings. Detailed magnetic studies allow us to establish the spin state of each nickel in these three complexes. Besides, three different torsion angles with the same ligand and metal provide us with an opportunity to examine the factors governing the helicity of rigid ligands.
A pilot study of red complex and three genera subgingival microbiome in periodontitis subjects with and without diabetes, evaluated by MinION platform
Authors: Bachtiar Boy M. , Theodorea Citra F. , Tahapary Dicky L. , Astrella Cindy , - Natalina , Bachtiar Endang W.
Published: July 2021

Background: Subgingival niche is one biofilm habitat containing rich microbiota, which plays an active role in maintaining the health of periodontal tissue and determining host response. As such, a study of changing subgingival biofilms is important for understanding the effect of a systemic condition. In this study, we compared the occurrence of six bacteria cohabiting in the subgingival area of periodontitis subjects, with (DP, n = 8) and without (NDP, n = 4) diabetes.

Methods: The six genus and species of targeted bacteria were confirmed by 16S rRNA amplicon sequencing on MinION nanopore platform. Descriptive statistic was used to describe the obtained data.

Results: We found that the six genus and species of targeted bacteria were detected but in different quantities in either group's periodontal pocket. Our data showed that Tannerella forsythia was the most abundant species in subgingival biofilms of the DP group of the red complex bacteria. In contrast, Aggregatibacter sp., which belongs to the phylum of proteobacteria, was present at a relatively lower level. In contrast, Fusobacterium sp., which belongs to orange complex bacteria, showed relative similarities in subgingival biofilms of both groups tested, while Veillonella sp., were abundant in the DP groups. 

Conclusions: Our data show that the diversity of classic periodontopathogens increased in the subgingival niche of periodontitis subjects with diabetes. It is the first study in Indonesia to apply MinION-based, full-length 16S rRNA amplicon sequencing in periodontitis patients with and without diabetes.
Psychological and clinical-epidemiological profile of poisoning in Nepal: an institutional experience
Authors: Basnet Angela , Shrestha Dhan , Chaulagain Sabin , Thapa Ashok , Khadka Manoj , Regmi Bishal , Khadka Manita , Adhikari Kabita , Thapa Anil Jung , Pokharel Sakar , Singh Kaushal Kumar , Syangtang Prajwal , Adhikari Surakchha
Published: July 2021

Background 

Poisoning has become a major public health problem, with the intent in most cases being self-harm and commit suicide. This study highlights the psychological and clinical-epidemiological profile of patients visiting Scheer Memorial Adventist Hospital after poisoning. 

Methods 

This retrospective record-based study was done among poisoning patients of a hospital in Nepal from 1st January 2018 to 31st December 2020. Data were analyzed using STATA version-15. 

Results 

Out of 134 total poisoning cases, 71 had consumed organophosphate compounds. The majority of the cases were female (59.2% in organophosphate groups, 69.8% in non-organophosphate groups). The circumstances of poisoning were mostly suicidal (95.8% in organophosphate groups, 90.5% in non-organophosphate groups) and the reasons for this being mostly family disputes. Organophosphate groups had 8.41 times higher odds of having complications when compared to non-organophosphorus compounds.  

Conclusions 

The majority of the poisoning cases were suicidal in nature and family disputes being the major reason for the intake of a poisonous substance. This demands that more attention be given to psychological and family counseling to resolve any disputes, as well as psychological management of poisoning cases after medical management. Also, a strong regulatory mechanism should be imposed to control the easy access to poisonous substances.
Sarcoidosis with Rare Extrapulmonary Involvement
Authors: Brandão Calçada Marta , Montezinho Sara , Teixeira Andreia M , Gomes Bruno , Macedo Bernardo
Published: July 2021

Sarcoidosis is a systemic granulomatous disease in which medullary involvement is a rare extrapulmonary manifestation. We present the case of a 37-year-old man with right abdominal and dorso-lumbar pain lasting for months. Computerized tomography showed renal microlithiasis and retroperitoneal, hilar and mediastinal adenopathies. Laboratory results showed an elevated erythrocyte sedimentation rate, IgG, ?2-microgobulin and angiotensin-conversion enzyme, serum calcium in the upper limit and hypercalciuria. There was a slight elevation of the CD4/CD8 ratio in bronchoalveolar lavage, without lymphocytic alveolitis. An endobronchial ganglion biopsy was inconclusive. A positron emission tomography scan demonstrated supra and infra-diaphragmatic, splenic and medullary involvement, suggesting lymphoproliferative disease (LPD). A bone marrow biopsy (BMB) revealed sarcoid-like epithelioid cell granulomas, excluding LPD. Sarcoidosis was assumed and corticosteroids were started. Although cytopenias were not present, the extensive ganglion, splenic and medullary involvement made LPD exclusion imperative, while BMB allowed for a definitive diagnosis.
Numerical convergence and stability of mixed formulation with X-FEM cut-off
Authors: Amdouni S. , Mansouri K. , Renard Y. , Arfaoui M. , Moakher M.
Published: July 2021

In this paper, we are concerned with the mathematical and numerical analysis of convergence and stability of the mixed formulation for incompressible elasticity in cracked domains. The objective is to extend the extended finite element method (X-FEM) cut-off analysis done in the case of compressible elasticity to the incompressible one. A mathematical proof of the inf-sup condition of the discrete mixed formulation with X-FEM is established for some enriched fields. We also give a mathematical result of quasi-optimal error estimate. Finally, we validate these results with numerical tests.
Level set propagation for mixed-mode crack advance
Authors: Colombo D. , Massin P.
Published: July 2021

In the extended finite element method framework, the advantage of being able to represent cracks independently from mesh rests on the use of level sets. Propagation simulation is connected to the update of these level sets, following the resolution of differential equations of evolution. In this document, we analyse these equations so that fast and robust mixed-mode propagation methods can be put forward. The proposed methodology can also manage the separation of a crack front into several fronts as well as the merging of several fronts during the propagation process. An example of 3D non-planar propagation is proposed at the end to show the efficiency of our choices.
Error control in FORM reliability analysis
Authors: Gallimard Laurent
Published: July 2021

This paper deals with the failure probability error induced by the coupling between the first-order reliability method (FORM) and the Finite Element Method (FEM). A FEM error estimator based on the concept of error in constitutive relation associated with goal-oriented error estimation is proposed. Furthermore an importance sampling technique is used to compute the error due to the FORM approximation. Both these errors are used to choose a finite element mesh adapted to the problem.
Robust control of PGD-based numerical simulations
Authors: Chamoin Ludovic , Ladevèze Pierre
Published: July 2021

In this paper, we develop an error estimator that enables to control effectively the quality of numerical solutions obtained using proper generalised decomposition. The method is based on the Constitutive Relation Error and the construction of associated admissible fields. It takes all error sources (discretisations, truncation of the modal representation, etc.) into account and can be used, introducing adjoint-based techniques, for goal-oriented error estimation. Furthermore, specific indicators can be derived to split error contributions and thus drive adaptive procedures in an optimal manner.
Hydrodynamic stability and turbulent transition with the Vreman LES SGS and a modified lattice Boltzmann equation
Authors: Murdock J. R. , Yang S. L.
Published: July 2021

For the evaluation of a broad range of Re in incompressible flows, particularly unsteady and transition regimes, the Vreman subgrid scale model is studied within the framework of a modified lattice Boltzmann equation. A unique multiple relaxation time form which recovers the fully incompressible unsteady Navier-Stokes equations is derived for the D3Q19 lattice. Solutions to the 3D-driven cavity are compared to a number of lattice Boltzmann and Navier-Stokes solutions. Initial simulations demonstrate the vanishing nature of eddy viscosity in the steady laminar regime. Onset of unsteadiness is found between Re 1900 and 1950, matching well with the wealth of literature. At Re 6000, velocity history and complex vortex structures show a transition to turbulence near the domain bottom and front walls while the centre of the domain retains laminar characteristics. By Re 8000 intermittent turbulence has progressed to the domain centre. This range of Re for transition and the flow characteristics are in agreement with the general ranges in literature, with further observations being added here. The Vreman model with an incompressible lattice Boltzmann method is found to be a promising tool for laminarto- turbulent simulation.
A high fidelity cost efficient tensorial method based on combined POD-HOSVD reduced order model of flow field
Authors: Moayyedi Mohammad Kazem , Beygi Milad Najaf
Published: July 2021

Computation time and data storage is a significant challenge in every calculation process. Increasing computational speed by upgrading hardware and the introduction of new software are some of the techniques to overcome this challenge. One of the most interesting methods for fast computations is the reduced order frameworks. In this study, the aerodynamic coefficients of the NACA0012 airfoil in subsonic and supersonic flows have been reconstructed and estimated by a cost-efficient form of combined proper orthogonal decomposition–high-order singular value decomposition (POD-HOSVD) scheme. The initial data ensemble contains some members related to the variations of the angle of attack and Mach number. To reduce the computation time, the structure of the standard combined POD-HOSVD approach has been changed to a cost-efficient format. The present method is a grid independent formulation of standard combined POD-HOSVD for the fields with a large number of elements and several effective variables. Results indicate more than 90 percent reduction in the calculation time compares with computational fluid dynamics and standard combined POD-HOSVD methods for a subsonic flow field.
3D simulation of the matter transport by surface diffusion within a level-set context
Authors: Bruchon Julien , Muñoz Daniel Pino , Valdivieso François , Drapier Sylvain , Pacquaut Guillaume
Published: July 2021

Within the framework of the sintering process simulation, this paper proposes a numerical strategy for the direct simulation of the matter transport by surface diffusion. A level-set method is used to describe the topological changes which arise at the free boundary of the sintering particles. The surface velocity is found to be proportional to the surface Laplacian of the curvature, that is, proportional to the fourth-order derivative of the level-set function. Consequently, both curvature and velocity must be computed carefully and with accuracy. Finally, three-dimensional simulations are shown and investigated.
Nonlinear transverse steady-state periodic forced vibration of 2-dof discrete systems with cubic nonlinearities
Authors: Eddanguir Ahmed , Beidouri Zitouni , Benamar Rhali
Published: July 2021

A method based on Hamilton’s principle and spectral analysis has been applied recently to nonlinear transverse vibrations of discrete systems with cubic nonlinearities, leading to calculation of the nonlinear free modes of transverse vibration and their associated nonlinear frequencies. The objective of the present work was the extension of this method to the nonlinear forced transverse steady-state periodic response of 2-dof system leading to nonlinear frequency response function in the neighbourhood of the two modes
Nonlinear dynamics of a bladed dual-shaft
Authors: Gruin Marion , Thouverez Fabrice , Blanc Laurent , Jean Pierrick
Published: July 2021

In the industrial context of performance improvement of dual-shaft aircraft engines, experimental results demonstrate how important it is to consider the influence of the dynamics of the high pressure (HP) shaft on the response of the bladed disk located on the low pressure (LP) shaft. Indeed, this coupling seems to play an important role in the design purposes in rotating machinery industry as it can have a significant impact on the dynamic behaviour of turbomachines. The model developed here consists of a HP shaft and a LP bladed shaft connected by an intershaft bearing. Nonlinear features of this intershaft bearing require the development of specific nonlinear algorithms. Thus, this paper aims at coupling the two modelling levels in order to grasp the nonlinear vibratory phenomena of a bladed dual-shaft under unbalances.
Damaged behavior under plane stress
Authors: Paris Thomas , Saanouni Khémaïs
Published: July 2021

This paper deals with the numerical treatment of "advanced" elasto-viscoplasticdamage constitutive equations in the particular case of plane stress. The viscoplastic constitutive equations account for the mixed isotropic and kinematic non linear hardening and are fully coupled with the isotropic ductile damage. The viscous effect is indifferently described by a power function (Norton type) or an hyperbolic sine function. Different time integration schemes are used and compared to each other assuming plane stress condition, widely used when dealing with shell structures as well as to the 3D reference case.
Sheet metal forming simulation using finite elastoplasticity with mixed isotropic/kinematic hardening
Authors: Chatti Sami , Chtioui Narjess
Published: July 2021

A numerical formulation is presented for anisotropic elastoplasticity behavior in finite strain with non-linear isotropic/kinematic hardening model. Non-linear kinematic hardening is modeled by the Lemaitre-Chaboche law with the aim of considering cyclic deformation phenomena. User-defined material subroutines are developed based on Hill’s quadratic yield function for both ABAQUS-Explicit (VUMAT) and ABAQUS-Standard (UMAT). For validation purpose, the tension-compression and cyclic shear tests are simulated. Several sheet forming processes including contact, anisotropic plasticity, elastic modulus variation with plastic strain and springback effects are simulated. Numerical results are compared with experimental data.
Long-term All-Cause Mortality Risk in Obstructive Sleep Apnea Using Hypopneas Defined by a ≥3 Percent Oxygen Desaturation or Arousal
Authors:   Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Boston, MA USA, Budhiraja Rohit , Quan Stuart
Published: July 2021

Study Objectives: Some prior studies have demonstrated an increase in mortality associated with obstructive sleep apnea (OSA) utilizing a definition of OSA that requires a minimum 4% oxygen desaturation to identify a hypopnea. No large community-based studies have determined the risk of long-term mortality with OSA with hypopneas defined by a ≥3% O2 desaturation or arousal (AHI3%A). Methods: Data from 5591 Sleep Heart Health Study participants without prevalent cardiovascular disease at baseline who underwent polysomnography were analyzed regarding OSA diagnosed using the AHI3%A criteria and all-cause mortality over a mean follow up period of 10.9±3.2 years. Results: There were 1050 deaths in this group during the follow-up period. A Kaplan-Meir plot of survival revealed a reduction in survival with increasing AHI severity. Cox proportional hazards regression models revealed significantly increased all-cause mortality risk with increasing AHI, hazard ratio (HR, 95% CI) 1.13 (1.04-1.23), after adjusting for age, sex, race, BMI, cholesterol, HDL, self-reported hypertension and/or diabetes and smoking status. In categorical models, the mortality risk was significantly higher with severe OSA [adjusted HR 1.38 (1.09-1.76)]. When stratified by gender or age, severe OSA was associated with increased risk of death in men [adjusted HR 1.14 (1.01-1.28)] and in those <70 years of age [adjusted HR 1.51 (1.02-2.26)]. In contrast, AHI severity was not associated with increased mortality in women or those ≥70 years of age in fully adjusted models. Conclusion: Severe AHI3%A OSA is associated with significantly increased mortality risk, especially in men and those <70 years of age.
Scintillation and BER analysis of cosine and cosine-hyperbolic-Gaussian beams in turbulent ocean
Authors: Keskin Aysan , Baykal Yahya
Published: July 2021

Effects of source beam, link, and oceanic turbulence parameters on the scintillation index and bit error rate (BER) performance of cosine (cos) and cosine-hyperbolic (cosh) Gaussian light beams have been investigated in order to improve wireless optical communication link performance in oceanic turbulence. The Nikishov and Nikishov power spectrum of oceanic water and extended Huygens Fresnel principle were used in our evaluations; the results were obtained via MATLAB. The scintillation index and BER were examined versus oceanic turbulence parameters, which are the rate of dissipation of mean-square temperature, the ratio of temperature and salinity contributions to the refractive index spectrum, and the dissipation rate of kinetic energy per unit fluid mass of fluid. Further, the scintillation index and BER are investigated against the source size, propagation distance, and complex displacement parameters of cos- and cosh-Gaussian beams. This study aimed to select the suitable sinusoidal beam to be employed in order to increase the performance of underwater wireless optical communication systems operating in oceanic turbulence.
Fraunhofer Institute of Optronics, System Technologies and Image Exploitation: introduction to the focus issue
Authors: Gładysz Szymon , Beyerer Jürgen , Eichhorn Marc
Published: July 2021

This focus issue offers a glimpse into the breadth and depth of research in optics and
image processing at the Fraunhofer Institute of Optronics, System
Technologies and Image Exploitation (abbreviated Fraunhofer IOSB). The
institute belongs to the Fraunhofer Society, which is Europe’s largest
organization for applied research. The society comprises 72 institutes
spread throughout Germany as well as subsidiaries in several European
countries, and the USA, UK, Chile and Singapore, each focusing on
different fields of applied science. It is named after the Bavarian
physicist Joseph von Fraunhofer (1787-1826), the inventor of the
spectrometer, optical lens manufacturer and an entrepreneur who
exemplified the goals of the society, i.e.: a focus on research
excellence, innovation, and commitment to market and customer-oriented
research.
Hard-aperture effect on self-focusing of high-power laser beams propagating in the atmosphere
Authors: Zhang Gan , Deng Yu , Ji Xiaoling
Published: July 2021

The hard-aperture effect on self-focusing of high-power laser beams propagating from the ground through the atmosphere to space orbits is studied. It is shown that the spot size on the target increases as the truncation parameter decreases and the beam power increases. However, as the truncation parameter decreases, the apertured laser beam is less affected by self-focusing. On the other hand, two effective design rules are presented to optimize the intensity on the target, i.e., the optimal power and the optimal focal length. It is proven that the self-focusing effect and the hard-aperture effect both can be compensated by applying the optimal initial beam defocusing. It is also found that the higher maximum intensity on the target will occur by applying the optimal focal length rather than the optimal power.
Phase retrieval and design with automatic differentiation: tutorial
Authors: Wong Alison , Pope Benjamin , Desdoigts Louis , Tuthill Peter , Norris Barnaby , Betters Chris
Published: July 2021

The principal limitation in many areas of astronomy, especially for directly imaging exoplanets, arises from instability in the point spread function (PSF) delivered by the telescope and instrument. To understand the transfer function, it is often necessary to infer a set of optical aberrations given only the intensity distribution on the sensor—the problem of phase retrieval. This can be important for post-processing of existing data, or for the design of optical phase masks to engineer PSFs optimized to achieve high-contrast, angular resolution, or astrometric stability. By exploiting newly efficient and flexible technology for automatic differentiation, which in recent years has undergone rapid development driven by machine learning, we can perform both phase retrieval and design in a way that is systematic, user-friendly, fast, and effective. By using modern gradient descent techniques, this converges efficiently and is easily extended to incorporate constraints and regularization. We illustrate the wide-ranging potential for this approach using our new package, Morphine. Challenging applications performed with this code include precise phase retrieval for both discrete and continuous phase distributions, even where information has been censored such as heavily saturated sensor data. We also show that the same algorithms can optimize continuous or binary phase masks that are competitive with existing best solutions for two example problems: an apodizing phase plate coronagraph for exoplanet direct imaging, and a diffractive pupil for narrow-angle astrometry. The Morphine source code and examples are available open-source, with an interface similar to the popular physical optics package Poppy.
Stress-matched laminated thin film of SiOxNy/SiO2/ SiOxNy for enhanced encapsulation of organic light-emitting devices
Authors: Chen Zheng , Wang Zhenyu , Zhou Yibin , Zhang Jian , Li Ze , Li Chuannan , Chen Ping , Duan Yu
Published: July 2021

The laminated structure of thin-film encapsulation (TFE) plays an important role for the reliability of organic light-emitting devices (OLEDs). In previous studies of TFE-structures, only the density of the films and the gas-barrier properties were taken into account, while a potential internal stress in the film was largely neglected. Internal stress issues can lead to cracks, warping, and delamination, which affect the performance of the encapsulation layer significantly. Finding ways to eliminate or perhaps utilize potential internal stresses of these films could have substantial benefits for future OLEDs. This study is at the forefront of the stress-related properties of TFE in conjunction with optoelectronic devices. We perform a moisture-barrier test of a fabricated encapsulated laminated structure (Si/50 nm SiOxNy/50nmSiO2/900 nm SiOxNy). The 50 nm SiOxNy buffer-layer was deposited (via chemical vapor deposition) to prevent the delamination and peeling between the SiO2 film and the OLEDs because of the high stress acting on the SiO2 layer. The water-vapor transmission rate of the laminated structure is below 5×10−5 g/m2·d at 38°C and 100% relative humidity. The concept of a laminated TFE-structure has a great application potential for future flexible and bendable organic optoelectronics.
Electric-field enhancement caused by subwavelength-sized particles located on the surface of multilayer dielectric mirrors
Authors: Huang H. , Kafka K. R. P. , Demos S. G.
Published: July 2021

A laser pulse impinging on the surface of an optical component can interact with particles, such as contamination debris, to produce a scattered electric field, which, either by itself or combined with the incident laser field, coherently can significantly increase the local field intensity. This effect can be of critical importance as it can reduce the laser-induced–damage threshold of the affected component. In this work, we use a field-propagation code to improve understanding regarding the factors that determine the magnitude and location of the electric-field enhancement for the case of subwavelength-sized particles located on the surface of multilayer dielectric mirrors.
Theoretical and experimental investigations on doubly Q-switched Tm:YAP laser with EOM and Sb2Te3 nanosheets
Authors: Niu Ziqun , Feng Tianli , Li Tao , Yang Kejian , Zhao Jia , Li Guiqiu , Li Dechun , Zhao Shengzhi , Qiao Wenchao , Chu Hongwei , Liu Yizhou
Published: July 2021

In this paper, two-dimensional material Sb2Te3 nanosheets are fabricated and the optical nonlinear response is investigated. A laser diode (LD) end-pumped doubly Q-switched Tm:YAP laser with electro-optic modulator (EOM) and Sb2Te3 nanosheets based saturable absorber (SA) is presented. The shortest pulse duration of 38 ns is achieved at the pulse repetition frequency of 100 Hz, corresponding to the highest peak power of 111.8 kW. The double Q-switching technique shows the advantages of pulse duration compression and peak power improvement. The coupled rate equations for the doubly Q-switched laser are developed and the corresponding numerical simulation agrees with the experimental results. We believe that the Sb2Te3 is a potential nanomaterial for the application in optoelectronic field.
Compact vectorial optical field generator using a single phase-only spatial light modulator
Authors: Lam Billy , Guo Chunlei
Published: July 2021

In this study, we demonstrate a compact vectorial optical field generator for any coherent light, including femtosecond laser beams. The apparatus utilizes a single Köster prism for both beam splitting and recombining. A phase-only spatial light modulator is used as a diffractive optical element to encode the two complex fields that recombine after being converted to orthogonal polarizations, generating an arbitrary vectorial optical field. We apply this setup to shape focused femtosecond pulses in producing patterned structures.
Predicting seasonal influenza using supermarket retail records
Authors: Miliou Ioanna , Xiong Xinyue , Rinzivillo Salvatore , Zhang Qian , Rossetti Giulio , Giannotti Fosca , Pedreschi Dino , Vespignani Alessandro
Published: July 2021

Increased availability of epidemiological data, novel digital data streams, and the rise of powerful machine learning approaches have generated a surge of research activity on real-time epidemic forecast systems. In this paper, we propose the use of a novel data source, namely retail market data to improve seasonal influenza forecasting. Specifically, we consider supermarket retail data as a proxy signal for influenza, through the identification of sentinel baskets, i.e., products bought together by a population of selected customers. We develop a nowcasting and forecasting framework that provides estimates for influenza incidence in Italy up to 4 weeks ahead. We make use of the Support Vector Regression (SVR) model to produce the predictions of seasonal flu incidence. Our predictions outperform both a baseline autoregressive model and a second baseline based on product purchases. The results show quantitatively the value of incorporating retail market data in forecasting models, acting as a proxy that can be used for the real-time analysis of epidemics.
Repeated evolution of circadian clock dysregulation in cavefish populations
Authors: Mack Katya L. , Jaggard James B. , Persons Jenna L. , Roback Emma Y. , Passow Courtney N. , Stanhope Bethany A. , Ferrufino Estephany , Tsuchiya Dai , Smith Sarah E. , Slaughter Brian D. , Kowalko Johanna , Rohner Nicolas , Keene Alex C. , McGaugh Suzanne E.
Published: July 2021

Circadian rhythms are nearly ubiquitous throughout nature, suggesting they are critical for survival in diverse environments. Organisms inhabiting largely arrhythmic environments, such as caves, offer a unique opportunity to study the evolution of circadian rhythms in response to changing ecological pressures. Populations of the Mexican tetra, Astyanax mexicanus, have repeatedly invaded caves from surface rivers, where individuals must contend with perpetual darkness, reduced food availability, and limited fluctuations in daily environmental cues. To investigate the molecular basis for evolved changes in circadian rhythms, we investigated rhythmic transcription across multiple independently-evolved cavefish populations. Our findings reveal that evolution in a cave environment has led to the repeated disruption of the endogenous biological clock, and its entrainment by light. The circadian transcriptome shows widespread reductions and losses of rhythmic transcription and changes to the timing of the activation/repression of core-transcriptional clock. In addition to dysregulation of the core clock, we find that rhythmic transcription of the melatonin regulator aanat2 and melatonin rhythms are disrupted in cavefish under darkness. Mutants of aanat2 and core clock gene rorca disrupt diurnal regulation of sleep in A. mexicanus, phenocopying circadian modulation of sleep and activity phenotypes of cave populations. Together, these findings reveal multiple independent mechanisms for loss of circadian rhythms in cavefish populations and provide a platform for studying how evolved changes in the biological clock can contribute to variation in sleep and circadian behavior.