bluuebunny/crossref_metadata_2025 huggingface dataset:
Association analysis of miRNA-related genetic polymorphisms in miR-143/145 and KRAS with colorectal cancer susceptibility and survival
Authors: Wang Danyang , Liu Qingmin , Ren Yanjun , Zhang Yan , Wang Xin , Liu Bing
Published: April 2021

Background: There is accumulating evidence of aberrant expression of miR-143 and miR-145 and their target gene KRAS in colorectal cancer (CRC). We hypothesize that single nucleotide polymorphisms (SNPs) within or near mRNA–microRNA (miRNA) binding sites may affect miRNA/target gene interaction, resulting in differential mRNA/protein expression and promoting the development and progression of CRC. Methods: We conducted a case–control study of 507 patients with CRC recruited from a tertiary hospital and 497 population-based controls to assess the association of genetic polymorphisms in miR-143/145 and the KRAS 3′ untranslated region (3′UTR) with susceptibility to CRC and patients’ survival. In addition, genetic variations of genomic regions located from 500 bp upstream to 500 bp downstream of the miR-143/miR-145 gene and the 3′UTR of KRAS were selected for analysis using the Haploview and HaploReg software. Results: Using publicly available expression profiling data, we found that miR-143/145 and KRAS expression were all reduced in rectal cancer tissue compared with adjacent non-neoplastic large intestinal mucosa. The rs74693964 C/T variant located 65 bp downstream of miR-145 genomic regions was observed to be associated with susceptibility to CRC (adjusted odds ratio (OR): 2.414, 95% CI: 1.385–4.206). Cumulative effects of miR-143 and miR-145 on CRC risk were observed (Ptrend=0.03). Patients having CRC carrying variant genotype TT of KRAS rs712 had poorer survival (log-rank P=0.044, adjusted hazard ratio (HR): 4.328, 95% CI: 1.236–15.147). Conclusions: Our results indicate that miRNA-related polymorphisms in miR-143/145 and KRAS are likely to be deleterious and represent potential biomarkers for susceptibility to CRC and patients’ survival.
Remodelling structure-based drug design using machine learning
Authors: Dutta Shubhankar , Bose Kakoli
Published: April 2021

To keep up with the pace of rapid discoveries in biomedicine, a plethora of research endeavors had been directed toward Rational Drug Development that slowly gave way to Structure-Based Drug Design (SBDD). In the past few decades, SBDD played a stupendous role in identification of novel drug-like molecules that are capable of altering the structures and/or functions of the target macromolecules involved in different disease pathways and networks. Unfortunately, post-delivery drug failures due to adverse drug interactions have constrained the use of SBDD in biomedical applications. However, recent technological advancements, along with parallel surge in clinical research have led to the concomitant establishment of other powerful computational techniques such as Artificial Intelligence (AI) and Machine Learning (ML). These leading-edge tools with the ability to successfully predict side-effects of a wide range of drugs have eventually taken over the field of drug design. ML, a subset of AI, is a robust computational tool that is capable of data analysis and analytical model building with minimal human intervention. It is based on powerful algorithms that use huge sets of ‘training data’ as inputs to predict new output values, which improve iteratively through experience. In this review, along with a brief discussion on the evolution of the drug discovery process, we have focused on the methodologies pertaining to the technological advancements of machine learning. This review, with specific examples, also emphasises the tremendous contributions of ML in the field of biomedicine, while exploring possibilities for future developments.
The Effect of Practice on Variability in Childhood Apraxia of Speech: A Multidimensional Analysis
Authors: Case Julie , Grigos Maria I.
Published: April 2021

Purpose

Variability has been interpreted in differing ways according to context (e.g., development, speech impairment, and learning). A challenge arises when interpreting variability in the context of learning for children with speech impairment characterized by high movement variability, as in childhood apraxia of speech (CAS). The objective of this study is to investigate changes in variability in CAS with practice in comparison to patterns seen in children with non-CAS speech sound disorders (SSD) and typical development.

Method

Speech production variability was examined in 24 children (5–6 years of age) with CAS, non—CAS SSD, and typical development in production of nonwords of varied motoric complexity. Multidimensional analyses were performed using measures of token-to-token speech consistency (percent word consistency), acoustic variability (acoustic spatiotemporal index), and movement variability (lip aperture spatiotemporal index). Changes in variability were examined in each group of children by comparing the first half to the last half of nonword tokens in the same data collection session. The impact of token complexity on practice effects was also explored across groups of children.

Results

All children displayed increased speech consistency within this practice period (
p =
.01). Only children with CAS displayed increased movement variability following practice (
p =
.01). Differences in acoustic and kinematic variability were observed across complexity levels in all groups, though these did not interact with practice effects.

Discussion

These findings suggest that increased movement variability in children with CAS might be facilitating perceptual consistency. It is believed that this finding reflects an inefficient strategy adapted by children with CAS in the absence of motor-based cueing and feedback to guide speech performance with practice.
Curriculum Vocabulary Learning of Fourth Graders Using the Vocabulary Scenario Technique
Authors: Spielvogel Joanna H. , Ehren Barbara J.
Published: April 2021

Purpose

The purpose of this study was to determine if a direct, explicit method of teaching vocabulary with the Vocabulary Scenario Technique – General Education 16 Encounter (VSTGE16) protocol would yield gains in the vocabulary knowledge of fourth grade students in a general education classroom. Two research questions examined whether fourth grade students receiving VST-GE16 instruction with 16 instructor-led encounters per word, eight words taught per week for 90 min a week over 4 weeks demonstrated greater gains on a multiple-choice synonym test and a fill-in-the-blank words-in-context test than fourth grade students taught the same number of words, in the same time frame, using a vocabulary teaching method typically employed by a fourth grade teacher.

Method

The study was a quasi-experimental design, with a pretest and posttest multiple-choice synonym and fill-in-the-blank words-in-context measures administered. Students with complete data sets were included in the analyses (synonym,
N
= 38; words-in-context,
N
= 37). Participants in both groups were taught eight curriculum vocabulary words per week for 90 min a week across four consecutive weeks (32 words).

Results

An analysis of covariance on posttreatment outcomes yielded the following: The treatment group scored significantly higher on the synonym measure,
F
(1, 35) = 14.76,
p
< .001;
g =
1.04, and the words-in-context measure,
F
(1, 34) = 43.66,
p
< .001;
g
= 1.59, than did the comparison group.

Conclusions

The results indicated that the VST-GE16 protocol has potential as an effective, efficient method to use when directly teaching curriculum vocabulary words to fourth grade students in general education classrooms
.
Failure analysis and lifetime assessment of IGBT power modules at low temperature stress cycles
Authors: Hernes Magnar , D'Arco Salvatore , Antonopoulos Antonios , Peftitsis Dimosthenis
Published: April 2021

Lifetime models of high‐power Insulated Gate Bipolar Transistors modules express the number of cycles to end of life as a function of stress parameters. These models are normally developed based on experimental data from accelerated power‐cycling tests performed at predefined temperature stress conditions as, for example, with temperature swings above 60 °C. However, in real power converters applications, the power modules are usually stressed at temperature cycles not exceeding 40 °C. Thus, extrapolating the parameters of lifetime models developed using data from high‐temperature stress cycles experiments might result in erroneous lifetime estimations. This paper presents experimental results from power cycling tests on high‐power Insulated Gate Bipolar Transistors modules subjected to low temperature stress cycles of 30 and 40 °C. Therefore, devices experience still accelerated aging but with stress conditions much closer to the real application. Post‐mortem failure analysis has been performed on the modules reaching end‐of‐life in order to identify the failure mechanism. Finally, the number of cycles to end‐of‐life obtained experimentally is fit with a state‐of‐the‐art lifetime model to assess its validity at low temperature stress cycles. Challenges and limitations on data fitting to this lifetime model and the impact of various stress parameters on the anticipated failure are also presented.
Black hole parameter estimation with synthetic very long baseline interferometry data from the ground and from space
Authors: Roelofs Freek , Fromm Christian M. , Mizuno Yosuke , Davelaar Jordy , Janssen Michael , Younsi Ziri , Rezzolla Luciano , Falcke Heino
Published: April 2021

Context.The Event Horizon Telescope (EHT) has imaged the shadow of the supermassive black hole in M 87. A library of general relativistic magnetohydrodynamics (GMRHD) models was fit to the observational data, providing constraints on black hole parameters.

Aims.We investigate how much better future experiments can realistically constrain these parameters and test theories of gravity.

Methods.We generated realistic synthetic 230 GHz data from representative input models taken from a GRMHD image library for M 87, using the 2017, 2021, and an expanded EHT array. The synthetic data were run through an automated data reduction pipeline used by the EHT. Additionally, we simulated observations at 230, 557, and 690 GHz with the Event Horizon Imager (EHI) Space VLBI concept. Using one of the EHT parameter estimation pipelines, we fit the GRMHD library images to the synthetic data and investigated how the black hole parameter estimations are affected by different arrays and repeated observations.

Results.Repeated observations play an important role in constraining black hole and accretion parameters as the varying source structure is averaged out. A modest expansion of the EHT already leads to stronger parameter constraints in our simulations. High-frequency observations from space with the EHI rule out all but ∼15% of the GRMHD models in our library, strongly constraining the magnetic flux and black hole spin. The 1σconstraints on the black hole mass improve by a factor of five with repeated high-frequency space array observations as compared to observations with the current ground array. If the black hole spin, magnetization, and electron temperature distribution can be independently constrained, the shadow size for a given black hole mass can be tested to ∼0.5% with the EHI space array, which allows tests of deviations from general relativity. With such a measurement, high-precision tests of the Kerr metric become within reach from observations of the Galactic Center black hole Sagittarius A*.
Non-linear dynamics of the minimal theory of massive gravity
Authors: Hagala Robert , De Felice Antonio , Mota David F. , Mukohyama Shinji
Published: April 2021

We investigate cosmological signatures of the minimal theory of massive gravity (MTMG). To this aim, we simulate the normal branch of the MTMG by employing the RAMSESN-body code and extending it with an effective gravitational constant Geff. We implement an environment-dependent Geff as a function of the graviton mass and the local energy density as predicted by MTMG. We find that halo density profiles are not a good probe for MTMG because deviations from general relativity (GR) are quite small. Similarly, the matter power spectra show deviations only at the percentage level. However, we find a clear difference between MTMG and GR in that voids are denser in MTMG than in GR. As measuring void profiles is quite a complex task from an observational point of view, a better probe of MTMG would be the halo abundances. In this case, MTMG creates a larger amount of massive halos, while there is a suppression in the abundance of small halos.
Nonthermal phenomena in the center of Abell 1775
Authors: Botteon A. , Giacintucci S. , Gastaldello F. , Venturi T. , Brunetti G. , van Weeren R. J. , Shimwell T. W. , Rossetti M. , Akamatsu H. , Brüggen M. , Cassano R. , Cuciti V. , de Gasperin F. , Drabent A. , Hoeft M. , Mandal S. , Röttgering H. J. A. , Tasse C.
Published: April 2021

Context. Thermal gas in the center of galaxy clusters can show substantial motions that generate surface-brightness and temperature discontinuities known as cold fronts. The motions may be triggered by minor or off-axis mergers that preserve the cool core of the system. The dynamics of the thermal gas can also generate radio emission from the intra-cluster medium (ICM) and impact the evolution of clusters’ radio sources.

Aims. We aim to study the central region of Abell 1775, a system in an ambiguous dynamical state at z = 0.072 which is known to host an extended head-tail radio galaxy, with the goal of investigating the connection between thermal and nonthermal components in its center.

Methods. We made use of a deep (100 ks) Chandra observation accompanied by LOFAR 144 MHz, GMRT 235 MHz and 610 MHz, and VLA 1.4 GHz radio data.

Results. We find a spiral-like pattern in the X-ray surface brightness that is mirrored in the temperature and pseudo-entropy maps. Additionally, we characterize an arc-shaped cold front in the ICM. We interpret these features in the context of a slingshot gas tail scenario. The structure of the head-tail radio galaxy “breaks” at the position of the cold front, showing an extension that is detected only at low frequencies, likely due to its steep and curved spectrum. We speculate that particle reacceleration is occurring in the outer region of this tail, which in total covers a projected size of ∼800 kpc. We also report the discovery of revived fossil plasma with ultra-steep spectrum radio emission in the cluster core together with a central diffuse radio source that is bounded by the arc-shaped cold front.

Conclusions. The results reported in this work demonstrate the interplay between thermal and nonthermal components in the cluster center and the presence of ongoing particle reacceleration in the ICM on different scales.
Space of signatures as inverse limits of Carnot groups
Authors: Le Donne Enrico , Züst Roger
Published: April 2021

We formalize the notion of limit of an inverse system of metric spaces with 1-Lipschitz projections having unbounded fibers. The construction is applied to the sequence of free Carnot groups of fixed rank n and increasing step. In this case, the limit space is in correspondence with the space of signatures of rectifiable paths in ℝn, as introduced by Chen. Hambly-Lyons’s result on the uniqueness of signature implies that this space is a geodesic metric tree. As a particular consequence we deduce that every path in ℝn can be approximated by projections of some geodesics in some Carnot group of rank n, giving an evidence that the complexity of sub-Riemannian geodesics increases with the step.
Integrated Community Onsite Sanitation System for Close Loop Faecal Management
Authors: Hastuti Elis , Riyana Rydha , Joy Benny , Supratman Unang , Pamekas R
Published: April 2021

The achievement of safe sanitation access is about 7.42 % in 2018, that indicates high risk of faecal contamination from unmanaged onsite sanitation system and has not been fully supported by faecal sludge service. This paper described the study of characteristic of onsite sanitation and faecal sludge for review potential of integrating of sludge handling with improved communal wastewater treatment. Faecal sludge quality were observed from pit latrines and communal septic tank, then analysis method apply cluster analysis and through close loop approach consider treatment and disposal for resource recovery. The pilot model of combined treatment of wastewater and faecal sludge was developed by anaerobic digester with a maximum 5% sludge loading, then further treatment by biofilter system and sludge drying bed. The quality of treated water can meet COD and nitrogen as effluent standard, biosolid reached a stabilization index of 40 - 60%, water content of 50-60% and less Coliform bacteria content. The characteristics of faecal sludge strength to be handled will be influenced bytechnical aspect or environment. The integrated system could be applied to manage wastewater and faecal sludge and its by products, mainly for rural area has not been catered by faecal sludge service.
Urban Farming as Women Empowerment: Case Study Sa’uyunan Sarijadi Women’s Farmer Group in Bandung City
Authors: Safitri Kinanti Indah , Abdoellah Oekan S , Gunawan Budhi
Published: April 2021

Urban farming activity in Bandung City contains an idea of women empowerment. That is because urban farming has done a lot by housewife. The Bandung City Government attempts to implement gender mainstreaming program in the development through urban farming. Therefore, an urban farming program in Bandung City designed by local government nowadays has four women’s farmer group. One of the women’s farmer group is Sa’uyunan Sarijadi. This research uses a case study from Sa’uyunan Sarijadi Women’s Farmer Group in Bandung, Indonesia. This study discusses the implementation urban farming as women empowerment in Sa’uyunan Sarijadi Women’s Farmer Group. The results showed that all of the members are involved in various production activities such as seeding, maintenance, hydroponic management for making herbal medicinal products derived from medicinal plants from the garden they plant. The sa’uyunan sarijadi women’s farmer group develop the creativity of housewives in carrying out agricultural production activities and making processed products from food crops. The motivation of women to be active in the management of urban farming because of the awareness to present organic and hygienic food consumption. Besides, the benefit of urban farming has provided economic benefits, social networks, and knowledge about providing healthy food.
Comparative Analysis of Three Implementation Model of Policies: Case Study in Acid Mine Drainage Management Policy in Indonesia
Authors: Armando Hutagalung Franky , Kurnani Tb. Benito A.
Published: April 2021

Policy implementation is one of the main elements of public policy to ensure that policy is successful in resolving all concerns and promoting the efforts made by the organization as a policy implementer. The implementation of public policies can be influenced by several factors, such as limited budget and human resources, lack of socialization, low commitment of authorized officials, including supervision and sanctions that have not been implemented properly. There are many models of public policy implementation, but policy implementation is still ineffective, especially in environmental policies. Some studies have been performed on the development of a policy implementation model with a range of methods and principles, three of them are policy implementation models developed by Van Horn-Van Meter; Grindle; Mazmanian and Sabatier. Those three methods are used respectively according to the existing conditions with different levels of achievement. The objective of this article is to assess the best model of policy implementation related to Acid Mine Drainage management policy of coal mining operations in Indonesia through a comparative study review. The results of the analysis show that the model developed by Mazmanian Sabatier is the most appropriate model to implement the policy of Acid Mine Drainage in Indonesia.
Bioconversion Rice Bran and Cassava Peel into Yeasts Cell Walls Mannoprotein as Environmental Friendly Antioxidant
Authors: Oktaviani Novia , Sarwono Ki Ageng , Utama Gemilang lara
Published: April 2021

Rice bran and cassava peel can be used as nutrients for yeast growth to produce mannoproteins. Currently, the application of yeast cell wall mannoproteins has only limited use in the food sector such as winemaking, stabilizers and emulsifiers in salad dressings. The functional and biological abilities of mannoproteins are influenced by their constituent components. Currently, has been found research that mannan and protein, which are components of mannoproteins, have potential as antioxidants. Based on a literature review, mannoproteins have potential as antioxidants because many hydroxyl groups are found in the chain of bonds. All mannan fractions have superior scavenging activity against hydroxyl groups at a concentration of 3.2 mg / mL while to produce scavenging activity against oxidative superoxide groups requires 3.3 mg / mL. Utilization of rice bran and cassava peels through the production of mannoproteins as antioxidants is an environmental friendly action because it can reduce the volume and utilize agro-industrial waste, so that environmental pollution can be better controlled.
Aqueous Systems of Dissolved Oxygen in Reservoir
Authors: Liqoarobby R , Sunardi  , Suparman Y , Fadilah K
Published: April 2021

Oxygen plays a crucial role in aquatic ecosystem particularly for supporting aquaculture and hydropower. In freshwater, importance of oxygen is for metabolic respiration and balance for heterotrophic organisms. Oxygen is also involved in various chemical equations in which compounds influence each other. To prevent oxygen depletion, understanding the changes in DO and all interactions with other water qualities been reviewed with purposed to know aqueous systems work. Photosynthesis by phytoplankton is the main production of dissolved oxygen. Carbon dioxide as output from respiration of microorganisms and degradation of organic inputs and light as energy transformation of photosynthesis is needed in the process. The temperature level is involved as a determinant of gas solubility. There is also gas exchange from atmosphere to water as oxygen diffusion that move toward an equilibrium. However, dissolved oxygen absorption occurs in high demand in case an oxidizer in the degradation of organic matter which come into the reservoir. In eutrophic condition, the abundance of phytoplankton also requires oxygen for respiration, especially at night. The consumption of dissolved oxygen often spurs reservoir managers to monitor the input into the reservoir to build an aerator as a form of ensuring adequate dissolved oxygen circulation.
Effect of different Mn doping and point vacancy ratios on the magnetic properties of ZnO
Authors: Hou Qingyu , Guan Yuqin , Wang Zhichao
Published: April 2021

The magnetic source of Mn doping and Zn vacancy coexisting in ZnO is controversial. To solve this problem, this work used the generalized gradient approximation first-principles plane-wave ultrasoft pseudo potential + U method based on density functional theory to calculate the effect of different Mn doping to point vacancy ratios on the magnetic properties of ZnO. The formation energy of ZnO with different Mn-substituted Zn (MnZn) to oxygen/zinc vacancy (VO/VZn) ratios can be smaller and more stable in zinc (Zn)-rich conditions than in oxygen (O)-rich conditions. The ZnO system exhibits p-type half-metallic ferromagnetism when the MnZn to VZn ratio is 2:1 or 2:2. When the Mn doping amount is constant, the Zn vacancies increase and the total magnetic moment of the doped system decreases. For the ZnO system in which Mn doping and oxygen vacancies coexist, when the amount of oxygen vacancies is constant, with Mn doping increase, the magnetic moment becomes larger. Both Zn22Mn2O22 and Zn20Mn2O24 can achieve ferromagnetic characteristics above room temperature.
A multivariate representation of compressed pin-by-pin cross sections
Authors: Tomatis Daniele
Published: April 2021

Since the 80’s, industrial core calculations employ the two-step scheme based on prior cross sections preparation with few energy groups and in homogenized reference geometries. Spatial homogenization in the fuel assembly quarters is the most frequent calculation option nowadays, relying on efficient nodal solvers using a coarse mesh. Pin-wise reaction rates are then reconstructed by dehomogenization techniques. The future trend of core calculations is moving however toward pin-by-pin explicit representations, where few-group cross sections are homogenized in the single pins at many physical conditions and many nuclides are selected for the simplified depletion chains. The resulting data model requires a considerable memory occupation on disk-files and the time needed to evaluate all data exceeds the limits for practical feasibility of multi-physics reactor calculations. In this work, we study the compression of pin-by-pin homogenized cross sections by the Hotelling transform in typical PWR fuel assemblies. The reconstruction of these quantities at different physical states of the assembly is then addressed by interpolation of only a few compressed coefficients, instead of interpolating separately each homogenized cross section. Savings in memory higher than 90% are observed, which result in important gains in runtime when interpolating the few-group data.
Dynamics of Human–Water Interactions in the Kilombero Valley, Tanzania: Insights from Farmers’ Aspirations and Decisions in an Uncertain Environment
Authors: Höllermann Britta , Näschen Kristian , Tibanyendela Naswiru , Kwesiga Julius , Evers Mariele
Published: April 2021

The Kilombero Valley, one of East Africa’s largest seasonal wetlands, is a high-potential agricultural development corridor area in Tanzania. This seasonally flooded wetland is mainly used by smallholder farmers who cultivate during the rainy season, although there are some community-based irrigation systems that reduce hydro-climatic risks. In this study, we aim to understand how farmers’ aspirations and visions about the future are related to the current agricultural practices and human–water interaction. We specifically investigate the differences between farmers from rainfed and irrigated agriculture by using focus group discussions. Analysis of the in-depth interviews highlights how farmers’ actions both shape and respond to this highly dynamic and uncertain environment. Furthermore, we identify a close link, driven by the farmers’ level of agency, between aspirations and expected agro-economic development. The heterogeneity of farmers’ agency and hence their ability to cope with change is not only based on the socioeconomic status but also on their perception of the physical environment. We thus recommend that attention is also paid to the capacity for coping with environmental challenges that influences the level of farmers’ aspiration.
Strengthening the Resilience of Vulnerable Communities: Results from a Quasi-experimental Impact Evaluation in Coastal Bangladesh
Authors: Béné Christophe , Haque Mahfuzul A. B. M.
Published: April 2021

At present, no clear consensus exists on how to assess resilience interventions in the field. In this paper we propose to measure the impact of the ECOFISH project, the objective of which was to strengthen the resilience of local fishing communities affected by recurrent crises in Bangladesh. The evaluation was based on a difference-in-difference (DiD) framework. The DiD analysis indicates that households who benefited from ECOFISH have a higher propensity to adopt positive responses than non-beneficiaries when hit by a shock. Those beneficiaries also report a statistically higher recovery rate (resilience). The analysis indicates however that the project did not manage to reduce the propensity of households to engage in detrimental coping strategies and that the long-term food and nutritional security of the beneficiaries has not yet visibly improved compared to the control group. Those different results are discussed in the light of the wider literature on resilience evaluation.
Quantum dynamics of the classical harmonic oscillator
Authors: Giannakis Dimitrios
Published: April 2021

A correspondence is established between measure-preserving, ergodic dynamics of a classical harmonic oscillator and a quantum mechanical gauge theory on two-dimensional Minkowski space. This correspondence is realized through an isometric embedding of the L2(μ) space on the circle associated with the oscillator’s invariant measure, μ, into a Hilbert space H of sections of a C-line bundle over Minkowski space. This bundle is equipped with a covariant derivative induced from an SO+(1, 1) gauge field on the corresponding inertial frame bundle, satisfying the Yang–Mills equations. Under this embedding, the Hamiltonian operator of a Lorentz-invariant quantum system, constructed as a geometrical Laplace-type operator on bundle sections, pulls back to the generator of the unitary group of Koopman operators governing the evolution of classical observables of the harmonic oscillator, with Koopman eigenfunctions of zero, positive, and negative eigenfrequencies corresponding to quantum eigenstates of zero (“vacuum”), positive (“matter”), and negative (“antimatter”) energies. The embedding also induces a pair of operators acting on classical observables of the harmonic oscillator, exhibiting canonical position–momentum commutation relationships. These operators have the structure of order-1/2 fractional derivatives and therefore display a form of non-locality. In a second part of this work, we study a quantum mechanical representation of the classical harmonic oscillator using a one-parameter family of reproducing kernel Hilbert spaces, K^τ, associated with the time-τ transition kernel of a fractional diffusion on the circle. As shown in recent work, these spaces are unital Banach *-algebras of functions. It is found that the evolution of classical observables in these spaces takes place via a strongly continuous, unitary Koopman evolution group, which exhibits a stronger form of classical–quantum consistency than the L2(μ) case. Specifically, for every real-valued classical observable in K^τ, there exists a quantum mechanical observable, whose expectation value is consistent with classical function evaluation. This allows for a description of classical state space dynamics, classical statistics, and quantum statistics of the harmonic oscillator within a unified framework.
Entangled photon-pair sources based on three-wave mixing in bulk crystals
Authors: Anwar Ali , Perumangatt Chithrabhanu , Steinlechner Fabian , Jennewein Thomas , Ling Alexander
Published: April 2021

Entangled photon pairs are a critical resource in quantum communication protocols ranging from quantum key distribution to teleportation. The current workhorse technique for producing photon pairs is via spontaneous parametric down conversion (SPDC) in bulk nonlinear crystals. The increased prominence of quantum networks has led to a growing interest in deployable high performance entangled photon-pair sources. This manuscript provides a review of the state-of-the-art bulk-optics-based SPDC sources with continuous wave pump and discusses some of the main considerations when building for deployment.
Optimizing Ohmic contacts to Nd-doped n-type SrSnO3
Authors: Saran Kumar Chaganti V. R. , Golani Prafful , Truttmann Tristan K. , Liu Fengdeng , Jalan Bharat , Koester Steven J.
Published: April 2021

We report the results of metal contact resistance, RC, to Nd-doped n-type SrSnO3 films grown by radical-based hybrid molecular beam epitaxy. Sc, Mn, Ti, Al, and Cr contact layers were deposited onto heavily doped SrSnO3 thin films. With no annealing, Al and Cr contacts were found to be highly resistive, while Sc, Mn, and Ti were more conductive, with Mn having the lowest RC of 11 ± 3 Ω-mm, immediately after liftoff. After Al2O3 passivation at 200 °C, Sc, Mn, and Ti contacts all showed Ohmic behavior, with Ti contacts having RC = 2.4 ± 0.3 Ω-mm and a resultant sheet resistance, RS, of 1.66 ± 0.07 kΩ/◻. Specific contact resistivity, ρC, values of 0.03, 0.2, and 0.5 mΩ-cm2 were determined for Ti, Sc, and Mn, respectively. Annealing at 300 °C did not result in any significant change in RC. An additional study was performed using Ti-contacts on bi-layer films consisting of a heavily doped cap layer grown on a moderately doped active layer. It was found that the RC (ρC) of Ti metal to the bi-layer films was ∼1 (2) order(s) of magnitude lower than on single-layer controls. Temperature-dependent analysis was used to extract the barrier height and doping effect for annealed Ti contacts. This work is an important step in evaluating SrSnO3 for use in high-performance and transparent electronic applications.
Prospects for application of ferroelectric manganites with controlled vortex density
Authors: Schmidt Heidemarie
Published: April 2021

There is an urgent need for multifunctional materials that can reduce the energy demands of microelectronic devices. In ferroelectric manganites (RMnO3), R = Tm, Lu, Er, Ho, Y, Yb, the spontaneous formation of one-dimensional (1D) closed and open loop vortices has been observed when the ferroelectric manganite is cooled over its ferroelectric ordering temperature [Li et al., Phys. Chem. Chem. Phys. 22, 14415–14432 (2020)], namely, 621 K (TmMnO3), 730 K (LuMnO3), 833 K (ErMnO3), 875 K (HoMnO3), 914 K (YMnO3), and 1350 K (YbMnO3). The applicability of ferroelectric YMnO3 thin films as an electroforming-free, unipolar memristor for artificial intelligence [Rayapati et al., Nanotechnology 31, 31LT01 (2020); J. Appl. Phys. 126, 074102 (2019); 124, 144102 (2018)] as the light-emitting material for double-sided electroluminescent devices [Schmidt et al., German patent pending DE102018117210.0 (17 July 2018)] and as a p-type conducting material with a large Seebeck coefficient for thermoelectrics has been demonstrated. It is expected that the vortices in ferroelectric manganites are highly conducting at room temperature. In this report, envisioned disruptive innovations based on ferroelectric manganite thin films with a top electrode and a bottom electrode where the vortex density can be reconfigured by an electric field are presented and discussed, namely, electroluminescence illumination, ultrasensitive thermoelectrics, and artificial intelligence and cryptography. Finally, a short outlook to potential applications of manganites whose vortex density is controlled by temperature gradients, electric field ramps, and light pulses in the area of low loss transformers, single photon detectors, and 5G components is given.
Key chemical reaction pathways in a helium-nitrogen atmospheric glow discharge plasma based on a global model coupled with the genetic algorithm and dynamic programming
Authors: Li Jing , Fang Chuan , Chen Jian , Li He-Ping , Makabe Toshiaki
Published: April 2021

Determination of the key chemical reaction pathways in cold atmospheric plasmas (CAPs) is of great importance not only for understanding the spatiotemporal evolutions of the key plasma parameters during discharges but also for improving the plasma materials processing qualities. In this paper, a novel chemical reaction reduction method (CRRM) is proposed by using the global fluid model coupled with the genetic algorithm and the dynamic programming technique. With the aid of this newly developed CRRM, the key chemical reaction pathways can be automatically screened with a high computational efficiency under a pre-set critical calculation accuracy for the atmospheric pure helium and helium–nitrogen glow discharge plasmas. By comparing the calculated key plasma parameters, e.g., the species number densities, electron temperatures, voltage–current characteristics, based on the simplified models and their corresponding full models with those of the experimentally measured data, the reliability of the CRRM itself and the established key chemical reaction database for the atmospheric pure helium and helium–nitrogen CAPs are validated. This research also provides a general method for screening the key chemical reaction pathways for various low-temperature plasma sources.
Coarse-grained molecular dynamics simulation of wettability and bleed out of capillary underfill
Authors: Ito Hiroshi , Matsumoto Shigenori , Suzuki Tomohisa , Sugii Taisuke , Terasaki Takeshi , Moriya Hiroshi
Published: April 2021

Coarse-grained molecular dynamics simulations were performed to elucidate the capillary flow process of liquid state capillary underfill (CUF), a sealing resin material. First, we ran a wettability simulation with the CUF consisting of a monomer with small and large fillers. We observed that a certain amount of the monomer spreads ahead on the substrate, while many fillers are left inside the droplet. This was confirmed by subsequent mean square deviation (MSD), which showed that the monomer had a higher MSD, 25–45 σ2, than the small and large fillers, which were 0.4–1.4 σ2 and 0.02–0.2 σ2, respectively. When one part of large fillers was replaced with small fillers, small fillers helped accelerate the wetting dynamics because they could move fast. However, when the small filler ratio was high (20%), the MSD of small fillers decreased. Next, we performed a capillary flow simulation in which the CUF flowed between parallel walls and observed that it formed a ridgeline at the upper wall edge. Small fillers contributed to a decreased flow time. However, when the small filler ratio was even higher, the flow time increased. Then, the small fillers slowed themselves down, as shown in the MSD. This is due to an increase in monomer interactions and less space to move. We also found that the bleed length decreased with an increase in the small filler ratio. This study clarified the effects of filler usage on the flow time and bleed length and contributed to new insight into the capillary actions and material design relevant to CUF.
Fast pulse shaping for a novel gated electron mirror
Authors: Klopfer Brannon B. , Koppell Stewart A. , Bowman Adam J. , Israel Yonatan , Kasevich Mark A.
Published: April 2021

We present the design and prototype of a switchable electron mirror, along with a technique for driving it with an arbitrary pulse shape. We employ a general technique for electronic pulse-shaping, where high fidelity of the pulse shape is required, but the characteristics of the system, which are possibly nonlinear, are not known. This driving technique uses an arbitrary waveform generator to pre-compensate the pulse, with a simple iterative algorithm used to generate the input waveform. This is a broadly applicable, general method for arbitrary pulse shaping. Driving our switchable electron mirror with a flat-top pulse, we demonstrate an improvement in rms error of roughly two orders of magnitude compared to an uncompensated waveform. Our results demonstrate the feasibility of high fidelity waveform reproduction in the presence of nonidealities, with immediate applications in the realization of novel electron optical components.
Rayleigh–Taylor mixing may account for the position anomaly in NIF microdot spectroscopy experiments
Authors: Poujade O. , Barrios M. A. , Baton S. , Blancard C. , Devriendt R. , Primout M.
Published: April 2021

The “microdot spectroscopy” experiment [Barrios et al., “Electron temperature measurements inside the ablating plasma of gas-filled Hohlraums at the National Ignition Facility,” Phys. Plasmas 23, 056307 (2016); Barrios et al., “Developing an experimental basis for understanding transport in NIF Hohlraum plasmas,” Phys. Rev. Lett. 121, 095002 (2018).] allows for a simultaneous measurement of the electron temperature (Te) and position of a patch of Mn and Co inside a Hohlraum, as described by Barrios et al. [“Electron temperature measurements inside the ablating plasma of gas-filled Hohlraums at the National Ignition Facility,” Phys. Plasmas 23, 056307 (2016).] HYDRA simulations systematically predicted a dot location further away from its starting location than observed in the experiment. In the article, integrated radiation hydrodynamics simulations with TROLL have led to the same trend as HYDRA. A new ad hoc treatment of laser absorption, through what we have called absorption multipliers, has been implemented in TROLL in order to mimic the effect of absorption mechanisms other than inverse-bremsstrahlung. It led to the instrumental conclusion that whatever physical phenomenon was responsible for the position anomaly must have occurred in the early stage. More precise simulations of the dot region, from early to late time, show that the position discrepancy can be explained by a Rayleigh–Taylor mixing of the dot into the ablator as it expands in the Hohlraum. This mixing tends to shift the simulated dot closer to the location measured in the experiment. However, the mixing also changes the interpretation of the electron temperature from the spectral line ratios.
Fast-ion orbit sensitivity of neutron emission spectroscopy diagnostics
Authors: Järleblad H. , Stagner L. , Salewski M. , Eriksson J. , Benjamin S. , Madsen B. , Nocente M. , Rasmussen J. , Schmidt B. S.
Published: April 2021

Fast ions in fusion plasmas often leave characteristic signatures in the plasma neutron emission. Measurements of this emission are subject to the phase-space sensitivity of the diagnostic, which can be mapped using weight functions. In this paper, we present orbit weight functions for the TOFOR and NE213 neutron diagnostics at the Joint European Torus, mapping their phase-space sensitivity in 3D orbit space. Both diagnostics are highly sensitive to fast ions that spend a relatively large fraction of their orbit transit times inside the viewing cone of the diagnostic. For most neutron energies, TOFOR is found to be relatively sensitive to potato orbits and heavily localized counter-passing orbits, as well as trapped orbits whose “banana tips” are inside the viewing cone of TOFOR. For the NE213-scintillator, the sensitivity is found to be relatively high for stagnation orbits.
Simulating the city traffic complexity induced by traffic light periods
Authors: Carrasco S. , Medina P. , Rogan J. , Valdivia J. A.
Published: April 2021

We revisited the global traffic light optimization problem through a cellular automata model, which allows us to address the relationship between the traffic lights and car routing. We conclude that both aspects are not separable. Our results show that a good routing strategy weakens the importance of the traffic light period for mid-densities, thus limiting the parameter space where such optimization is relevant. This is confirmed by analyzing the travel time normalized by the shortest path between the origin and destination. As an unforeseen result, we report what seems to be a power-law distribution for such quantities, indicating that the travel time distribution slowly decreases for long travel times. The power-law exponent depends on the density, traffic light period, and routing strategy, which in this case is parametrized by the tendency of agents to abandon a route if it becomes stagnant. These results could have relevant consequences on how to improve the overall traffic efficiency in a particular city, thus providing insight into useful measurements, which are often counter-intuitive, which may be valuable to traffic controllers that operate through traffic light periods and phases.
Tailoring magnetization reversal of a single-domain bar nanomagnet via its end geometry
Authors: Li Jianhua , Dong Sining , Yue Wen-Cheng , Yuan Zixiong , Xiao Zhi-Li , Lyu Yang-Yang , Wang Ting-Ting , Li Chong , Wang Chenguang , Xu Wen-Bing , Dong Ying , Wang Huabing , Wu Peiheng , Kwok Wai-Kwong , Wang Yong-Lei
Published: April 2021

Nanoscale single-domain bar magnets are building blocks for a variety of fundamental and applied mesoscopic magnetic systems, such as artificial spin ices, magnetic shape-morphing microbots, and magnetic majority logic gates. The magnetization reversal switching field of the bar nanomagnets is a crucial parameter that determines the physical properties and functionalities of their constituted artificial systems. Previous methods on tuning the magnetization reversal switching field of a bar nanomagnet usually relied on modifying its aspect ratio, such as its length, width, and/or thickness. Here, we show that the switching field of a bar nanomagnet saturates when extending its length beyond a certain value, preventing further tailoring of the magnetization reversal via aspect ratios. We showcase a highly tunable switching field of a bar nanomagnet by tailoring its end geometry without altering its size. This provides an easy method to control the magnetization reversal of a single-domain bar nanomagnet. It would enable new research and/or applications, such as designing artificial spin ices with additional tuning parameters, engineering magnetic microbots with more flexibility, and developing magnetic quantum-dot cellular automata systems for low power computing.
Acoustic control of magnetism toward energy-efficient applications
Authors: Yang Wei-Gang , Schmidt Holger
Published: April 2021

The control of magnetism by acoustically induced strain has driven significant research activities, with the ultimate goal of pursuing novel, ultrafast, compact, and energy-efficient electronic and spintronic applications. Here, we aim to present for the first time a comprehensive review of this field, which has seen a surge of interest in recent years. We review fundamental understanding of magnetoelastic coupling phenomena and mechanisms, diverse experimental configurations, recent advances in modeling and microscopic tools to intuitively describe them, and the experimental and theoretical exploration of devices and technological innovations. These include acoustic spintronics, surface acoustic wave (SAW)-assisted spin transfer torque (STT) switching, SAW-assisted all-optical switching (AOS), SAW-driven spin textures (e.g., Skyrmions and domain walls), acoustic Terahertz emitters, SAW magnetic field sensors, magnetoelastic antenna, on-demand magnonic crystals, and so on. Focusing on the translation of many fundamental research breakthroughs into potential technological applications, we identify the key challenges and opportunities in the field, which we hope may motivate further research efforts of moving scientific discoveries toward real applications.
Applications of chip-scale semiconductor metamaterials based on plasmon-induced transparency in modulation and sensing
Authors: Han Lei , Tan Qiulin , Li Huan , Xiong Jijun , Zhang Wendong
Published: April 2021

We propose and simulate the tunable plasmon-induced transparency (PIT) phenomenon of semiconductor-based H-shaped chip-scale metamaterials. Numerical analysis shows that the PIT phenomenon is caused by the destructive interference between two bright modes, and the equivalent Lorentz model also proves its physical mechanism appropriately. In addition, in practical applications, changing the polarization angle can adjust the group delay, and the maximum group delay is 41.92 ps; changing the temperature can adjust the transmission peak frequency of the PIT effect, which can be applied to temperature sensing and thermo-optic switches. The amplitude modulation depth can reach 97.8%. The application of this chip-scale semiconductor metamaterial in modulators and sensors opens up new ways.