Miracle-dz/UniFAR-FTUs huggingface dataset:
Ejection of atoms and molecules from Io by plasma-ion impact

We examine models for ejection of atoms from the surface of Io or from an atmosphere on Io by plasma ion bombardment. We consider direct collisional ejection from an exosphere, surface sputtering, and atmospheric sputtering produced by this bombardment, as well as Jeans escape. Each of the ejection processes considered produces a distinctive directional and energy distribution for the ejected neutral flux and different ejection rates. These distributions and rates are compared to the source distributions suggested by Pilcher et al. for the observed neutral Na clouds associated with Io. We first show that a description of direct collision ejection requires the use of reasonable interaction potentials. Single collision ejection of ''atmospheric'' sodium has a directional and energy distribution distinctly characteristic of the source for the fast-sodium feature, while other ejection mechanisms are better models for the Na B-cloud. A combination of atmospheric sputtering (multiple collisions) and direct collisional ejection gives a directional and energy distribution as well as the supply rate consistent with that required to describe the full Na neutral cloud if the atmosphere is well mixed so that molecular species exist at the exobase. If molecular species do occur at the exobase, then other processes, such asmore » molecular dissociation by the plasma electrons, will also contribute. Surface sputtering also gives a reasonable source distribution but, based on the assumptions made here, the ejection rate appears to be too low. « less
An active hearing protection device for musicians

Professional musicians have to deal with two main problems when wearing hearing protection devices (HPDs): the occlusion effect and the isolation effect. The occlusion effect is an unnatural and annoying perception of one's own voice when wearing HPDs. It will affect all musicians whose instrument induces vibrations to the skull, including singers and musicians whose instrument is pressed against any part of the head. The isolation effect is the unnatural sensation of being isolated from a given sound environment. It is caused by a non-uniform attenuation of the HPD over the audio spectrum and the absence of compensation for equal loudness contours. These two effects are highly unfavorable to the musicians' auditory perception and compromise their capacity to perform to the best of their abilities for their audience. This paper presents an active HPD for musicians, providing occlusion effect reduction and isolation effect compensation. Preliminary performance of the occlusion effect reduction system is pr.
Domain Swapping between AtACS7 and PpACL1 Results in Chimeric ACS-like Proteins with ACS or Cβ-S Lyase Single Enzymatic Activity

The gaseous hormone ethylene plays a pivotal role in plant growth and development. In seed plants, the key rate-limiting enzyme that controls ethylene biosynthesis is ACC synthase (ACS). ACS has, for a long time, been believed to be a single-activity enzyme until we recently discovered that it also possesses Cβ-S lyase (CSL) activity. This discovery raises fundamental questions regarding the biological significance of the dual enzymatic activities of ACS. To address these issues, it is highly necessary to obtain ACS mutants with either ACS or CSL single activity. Here, domain swapping between Arabidopsis AtACS7 and moss CSL PpACL1 were performed. Enzymatic activity assays of the constructed chimeras revealed that, R10, which was produced by replacing AtACS7 box 6 with that of PpACL1, lost ACS but retained CSL activity, whereas R12 generated by box 4 substitution lost CSL and only had ACS activity. The activities of both chimeric proteins were compared with previously obtained single-activity mutants including R6, AtACS7Q98A, and AtACS7D245N. All the results provided new insights into the key residues required for ACS and CSL activities of AtACS7 and laid an important foundation for further in-depth study of the biological functions of its dual enzymatic activities.
Research collaboration networks in Latin American geography education

The current development of science is characterized by a global trend of scientific collaboration (SC). However, this growth has been mostly linked to intra-national cooperation. Several factors including geographic, institutional, and social proximities have been identified as key for promoting or hinder collaboration among scholars. Based on these premises, the present study analyses the co-authorship and affiliation relationships among geography education researchers in Latin America, exploring through a general trend and social network analysis, the characteristics of SC in geography education. For this purpose, 1774 articles (922 co-authored) published within the region were included as part of the data used for understanding the structure of SC. The results showed an increasing and dominant pattern of co-authoring in the region, but mostly developed at the local and national scale, with scarce intra-regional research. Moreover, the network analysis showed that there are some institutions with a dominant role in the production of research, and a loose network structure of research that could foster diverse perspectives on the field. These findings offer opportunities for thinking about how to enhance future SC processes in the region to strengthen the development of geography education research based on a regional collaborative approach.
Uncertainties Associated with Combining Airborne and Ground-Based Doppler Radar Data

Abstract Observations with airborne Doppler radar can expand the area of coverage and extend the time a moving weather system can remain under observation. Also, additional analysis methods are possible with the increase in independent estimates of the wind field that can be provided by an airborne sampling system. However, the advantages of airborne Doppler sensing are constrained by the geometry in which the data are collected, as well as errors introduced by uncertainties in the sampling platform location and orientation. Finally, a longer time required to sample a region than is typical for ground-based radar results in increased uncertainties due to the field's evolution and advection during the sampling interval. Uncertainties related to geometry are examined for flight patterns which are for aircraft alone and for those which also utilize data from one and two ground-based radars. These illustrate the distribution and relative magnitude of uncertainty expected for each type of flight pattern and da.
Dual-tree complex wavelet transform applied on color descriptors for remote-sensed images retrieval

Abstract. This paper highlights color component features that improve high-resolution satellite (HRS) images retrieval. Color component correlation across image lines and columns is used to define a revised color space. It is designed to simultaneously take both color and neighborhood information. From this space, color descriptors, namely rotation invariant uniform local binary pattern, histogram of gradient, and a modified version of local variance are derived through dual-tree complex wavelet transform (DT-CWT). A new color descriptor called smoothed local variance (SLV) using an edge-preserving smoothing filter is introduced. It is intended to offer an efficient way to represent texture/structure information using an invariant to rotation descriptor. This descriptor takes advantage of DT-CWT representation to enhance the retrieval performance of HRS images. We report an evaluation of the SLV descriptor associated with the new color space using different similarity distances in our content-based image retrieval scheme. We also perform comparison with some standard features. Experimental results show that SLV descriptor allied to DT-CWT representation outperforms the other approaches.
Discovery of interstellar water lines at 437, 439, and 471 GHz : strong case for water maser formation behind C-type shocks

We report the first astronomical detections of the 7 53 →6 60 , 6 43 →5 50 , and 6 42 →5 51 transitions of water vapor (H 2 O) at frequencies near 437, 439, and 471 GHz, respectively. Using the Caltech Submillimeter Observatory we detected the 439 and 471 GHz lines toward a number of star-forming regions and the 437, 439, and 471 GHz lines toward several evolved stars. Maser action is likely to be present in all of these lines. The previously detected 325 GHz 5 15 →4 22 H 2 O maser line was also observed toward these sources
Radiometry and Photometry

In order to reduce the confusion associated with many of the introductory treatments of photometry, it is suggested that initially the concepts of radiation transfer be introduced in terms of the more familiar units of radiometry. The conversion to photometric units can then be accomplished by a straightforward integration. The approach is illustrated with five of the basic quantities of radiometry.
An evaluation model based on procedural behaviors for predicting MOOC learning performance: students' online learning behavior analytics and algorithms construction

Purpose The purpose of this study is to set up an evaluation model to predict massive open online courses (MOOC) learning performance by analyzing MOOC learners’ online learning behaviors, and comparing three algorithms – multiple linear regression (MLR), multilayer perceptron (MLP) and classification and regression tree (CART). Design/methodology/approach Through literature review and analysis of data correlation in the original database, a framework of online learning behavior indicators containing 26 behaviors was constructed. The degree of correlation with the final learning performance was analyzed based on learners’ system interaction behavior, resource interaction behavior, social interaction behavior and independent learning behavior. A total of 12 behaviors highly correlated to learning performance were extracted as major indicators, and the MLR method, MLP method and CART method were used as typical algorithms to evaluate learners’ MOOC learning performance. Findings The behavioral indicator framework constructed in this study can effectively analyze learners’ learning, and the evaluation model constructed using the MLP method (89.91%) and CART method (90.29%) can better achieve the prediction of MOOC learners’ learning performance than using MLR method (83.64%). Originality/value This study explores the patterns and characteristics among different learning behaviors and constructs an effective prediction model for MOOC learners’ learning performance, which can help teachers understand learners’ learning status, locate learners with learning difficulties promptly and provide targeted instructional interventions at the right time to improve teaching quality.
Remarks on the L1 distance in statistical data analysis

ABSTRACT We propose the L1 distance between the distribution of a binned data sample and a probability distribution from which it is hypothetically drawn as a statistic for testing agreement between the data and a model. We study the distribution of this distance for N-element samples drawn from k bins of equal probability and derive asymptotic formulae for the mean and dispersion of L1 in the large-N limit. We argue that the L1 distance is asymptotically normally distributed, with the mean and dispersion being accurately reproduced by asymptotic formulae even for moderately large values of N and k.
Technology Acceptance of Indonesian Gen Z in Ticket Booking Platform: A Comparison of E-Commerce and Airline App

Currently, the popularity of booking airline tickets through online platforms is more desirable than buying from travel agents, especially for Indonesian Generation Z, who was born and grew up with technology. However, until now, research related to the adoption of online platforms is still separated between e-commerce and airline applications. Therefore, this study aims to analyze both. In this study, the success of UTAUT 2 in analyzing consumer adoption behavior has resulted. Although the results of respondents said that the adoption value for e-commerce was higher than airline applications, namely 4.38 and 1.62, the results stated that all respondents had used these two types of platforms, although with different frequencies. Furthermore, the descriptive analysis of each instrument shows that for Gen Z, the “Price Value” factor is the most prominent for airline applications, and the “Habit” factor is the most powerful for e-commerce. With these results, it is hoped that the relevant stakeholders can use the results of this study as a reference to improve the quality of their services.
Design of a collimator support to provide flexure control on Cassegrain spectrographs

The Echellette Spectrograph and Imager (ESI) is being built at UCO/Lick Observatory for the Cassegrain focus of the Keck II telescope. The collimator mirror is optimally constrained by a space-frame structure. It will be actively moved to provide the focus and flexure (tip and tilt) control for the instrument. Careful attention to space-frame geometry has simplified the mechanical design. Analytical and Finite Element Analysis (FEA) are presented to demonstrate how a simple but very stiff structure is used to provide support, flexure control, and focus.
A plastic optical fibre sensor for real-time humidity monitoring

Certain kinds of cellulose, such as a hydroxyethylcellulose, swell in a humid atmosphere and show a decrease in refractive index. Using this effect, a simple optical humidity sensor with fast response and high sensitivity, which is based on the plastic optical fibre structure change from leaky to guided, was easily fabricated and could be used for real-time humidity monitoring.
Chandra High-Resolution Spectroscopy of the Absorption-Line Features in the Low-Mass X-Ray Binary GX 13+1

We present the results of high-resolution spectroscopy of absorption-line features of highly ionized ions in the X-ray spectra of GX 13+1 with the Chandra HETGS. We have resolved Kα absorption lines of hydrogen-like Fe, Mn, Cr, Ca, Ar, S, Si, and Mg ions and helium-like Fe ions. Applying the Voigt profile to these spectral features, we find that the plasma responsible for the absorption lines has a significant blueshift of 460 ± 70 km s-1, indicating an outflow velocity of ≈400 km s-1 corrected for the proper motion, with a line-of-sight velocity dispersion of 490 km s-1. The plasma is photoionized with an ionization parameter of log ξ ≃ 4.1-4.7. The inferred mass outflow rate is 0.7 × 1018 g s-1 or higher, comparable to the mass accretion rate (1018 g s-1) estimated from the continuum spectrum. This indicates that the mass outflow plays a significant role to determine the whole dynamics of the accretion disk. We consider a simplified radiation-driven disk wind model for the origin of the outflow. Our observations are explained by the wind originating from radii of ~1010-1011 cm with a density ≳1013 cm-3.
Treatment of pancreatic cancer in 2022

Pancreatic ductal adenocarcinoma (PDAC) is usually diagnosed at an advanced, incurable, stage and has an extremely poor prognosis. Systemic chemotherapy represents the standard treatment either in the pre-operative, adjuvant and palliative setting, which is associated with only modest improvement in survival. More recently, advances in cancer genomic sequencing have unravelled the molecular heterogeneity of PDAC and identified small patient subgroups harbouring unique actionable aberrations in BRCA, NTRK, NRG1 and mismatch repair genes paving the way to a more personalised approach for this tumour. However, the evolution of PDAC treatment towards a successful precision approach presents many challenges. In this review, we discuss the current standard treatments of PDAC, from early stage to advanced disease, and we illustrate the opportunities and challenges of precision medicine for this deadly cancer.
Deregulated E2F Activity as a Cancer-Cell Specific Therapeutic Tool

The transcription factor E2F, the principal target of the tumor suppressor pRB, plays crucial roles in cell proliferation and tumor suppression. In almost all cancers, pRB function is disabled, and E2F activity is enhanced. To specifically target cancer cells, trials have been undertaken to suppress enhanced E2F activity to restrain cell proliferation or selectively kill cancer cells, utilizing enhanced E2F activity. However, these approaches may also impact normal growing cells, since growth stimulation also inactivates pRB and enhances E2F activity. E2F activated upon the loss of pRB control (deregulated E2F) activates tumor suppressor genes, which are not activated by E2F induced by growth stimulation, inducing cellular senescence or apoptosis to protect cells from tumorigenesis. Deregulated E2F activity is tolerated in cancer cells due to inactivation of the ARF-p53 pathway, thus representing a feature unique to cancer cells. Deregulated E2F activity, which activates tumor suppressor genes, is distinct from enhanced E2F activity, which activates growth-related genes, in that deregulated E2F activity does not depend on the heterodimeric partner DP. Indeed, the ARF promoter, which is specifically activated by deregulated E2F, showed higher cancer-cell specific activity, compared to the E2F1 promoter, which is also activated by E2F induced by growth stimulation. Thus, deregulated E2F activity is an attractive potential therapeutic tool to specifically target cancer cells.
Dimensionality reduction-based dynamic reconstruction algorithm for electrical capacitance tomography

The image reconstruction task in electrical capacitance tomography (ECT) is an ill-posed problem, in which image reconstruction methods play a vital role in real applications. In this paper, a multiple measurement vector-based dimensionality reduction dynamic reconstruction model that simultaneously utilizes the ECT measurement information and the dynamic evolution information of a dynamic object is proposed. A robust sparse orthogonal projective non-negative matrix factorization (RSOPNMF) method is proposed for extracting the basis vectors from a set of snapshots, and the split Bregman iteration (SBI) algorithm is used to solve the RSOPNMF model. The original unknown variables are projected onto the subspaces spanned by a set of the basis vectors extracted by the RSOPNMF method from a set of snapshots to obtain a low-dimensional model, where the images are indirectly reconstructed by solving the corresponding low-dimensional coefficient vector, and thus the dimensionality of the unknown variables is reduced and the computational cost are decreased. Based on the multiple measurement vectors and the dimensionality reduction model, an objective functional that incorporates the ECT measurement information, the dynamic evolution information of a dynamic object, the spatial constraint and the temporal constraint is proposed, in which the unknown variables are solved in a batching pattern. An iterative scheme that integrates the beneficial advantages of the SBI method and the forward–backward splitting algorithm is developed for solving the proposed objective functional. Numerical simulation results validate the feasibility of the proposed algorithm.
The destruction and survival of polycyclic aromatic hydrocarbons in the disks of T Tauri stars

In Spitzer observations of Tauri stars and their disks, features of polycyclic aromatic hydrocarbons (PAHs) are detected in less than 10% of the objects, although the stellar photosphere is sufficiently hot to excite PAHs. To explain the deficiency, we discuss PAH destruction by photons, assuming that the star has beside its photospheric emission also a far ultraviolet (FUV), an extreme ultraviolet (EUV) and an X-ray component with a fractional luminosity of 1%, 0.1% and 0.025%, respectively. We consider as a PAH destruction process unimolecular dissociation and present a simplified scheme to estimate the location from the star at which the molecules become photo-stable. We find that soft photons with energies below ∼20 eV dissociate PAHs only up to short distances from the star (r < 1 AU); whereas dissociation by hard photons (EUV and X-ray) is so efficient that it would destroy all PAHs (from regions in the disk where they could be excited). As a possible path for PAH-survival we suggest turbulent motions in the disk. They can replenish or remove PAHs from the reach of hard photons. For standard disk models, where the surface density changes like r −1 and the mid plane temperature like r −0.5 , the critical vertical velocity for PAH survival is proportional to r −3/4 and equals ∼ 5m / sa t 10 AU, which is in the range of expected velocities in the surface layer. The uncertainty in the parameters is large enough to explain both detection and non-detection of PAHs. Our approximate treatment also takes into account the presence of gas which is ionized at the top of the disk and neutral at lower levels.
A quantitative model for the potential resulting from reconnection with an arbitrary interplanetary magnetic field

A three-dimensional model is utilized to derive the electric potential induced across the magnetosphere by reconnection between the geomagnetic field and an arbitrary interplanetary magnetic field. Assumptions that the magnetosheath flow is uniform and that reconnection is not limited by processes occurring at the magnetopause are made so that the model calculation provides an upper limit to the magnetospheric potential produced by reconnection. The magnitude of the polar cap ionospheric electric field computed from this model is larger than that measured on balloons by an average factor of about 3, and the model reproduces the temporal variations of the experimental data. Some magnetospheric properties related to the magnetopause reconnection line and potential are discussed as a first suggestion toward using the model in studies of relevant magnetospheric problems. The model potential induced across the magnetosphere becomes less dependent on the direction of the interplanetary magnetic field as the strength of its transverse component increases. Thus a reduced correlation between magnetospheric phenomena and the southward component of the interplanetary field should exist when the transverse interplanetary field component exceeds about 8 γ. Observed dependences of the polar cap ionospheric current system on By are explained by the model, and similar variations with Bx are predicted. Graphs of the model potential as functions of the interplanetary magnetic field components are given as an aid in its application to other problems.
Performance of Wireless Powered Communication Systems Over Beaulieu-Xie Channels With Nonlinear Energy Harvesters

Performance of wireless powered wireless systems is analyzed. The wireless devices in such systems scavenge energy from sources in downlinks and use the energy to communicate in uplinks. We introduce two new models for these energy harvesters to consider their nonlinear circuitry and their functioning over multiple line-of-sight and non-line-of-sight channels. The newly proposed Beaulieu-Xie fading model is used to characterize this manifold of channels. Performance analyses of average harvested energy and transmission outage probability show good fit between the proposed models and measured data.