bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanoflare Theory Revisited
Authors: Jafari Amir , Vishniac Ethan T. , Xu Siyao 
Published: January 2021

Abstract
At any scale l in the turbulent inertial range, the magnetic field can be divided up into a large-scale component and a small-scale, high spatial frequency component which undergoes magnetic reversals. Such local reconnections, i.e., on any inertial scale l, seem to be an inseparable part of magnetohydrodynamic (MHD) turbulence, whose collective outcome can lead to global reconnection with a rate independent of the small-scale physics dominant at dissipative scales. We show that this picture, known as stochastic reconnection, is intimately related to nanoflare theory, proposed long ago to explain solar coronal heating. We argue that, due to stochastic flux freezing, a generalized version of magnetic flux freezing in turbulence, the field follows the flow in a statistical sense. Turbulence bends and stretches the field, increasing its spatial complexity. Strong magnetic shears associated with such a highly tangled field can trigger local reversals and field annihilations on a wide range of inertial scales which convert magnetic energy into kinetic and thermal energy. The former may efficiently enhance turbulence and the latter heat generation. We support this theoretical picture using scaling laws of MHD turbulence and also recent analytical and numerical studies which suggest a statistical correlation between magnetic spatial complexity and energy dissipation. Finally, using an MHD numerical simulation, we show that the time evolution of the magnetic complexity is statistically correlated with the rate of kinetic energy injection and/or magnetic-to-thermal energy conversion, in agreement with our proposed theoretical picture.
COOL-LAMPS. I. An Extraordinarily Bright Lensed Galaxy at Redshift 5.04*
Authors: Khullar Gourav , Gozman Katya , Lin Jason J. , Martinez Michael N. , Matthews Acuña Owen S. , Medina Elisabeth , Merz Kaiya , Sanchez Jorge A. , Sisco Emily E. , Kavin Stein Daniel J. , Sukay Ezra O. , Tavangar Kiyan , Bayliss Matthew B. , Bleem Lindsey E. , Brownsberger Sasha , Dahle HÅkon , Florian Michael K. , Gladders Michael D. , Mahler Guillaume , Rigby Jane R. , Sharon Keren , Stark Antony A. 
Published: January 2021

Abstract
We report the discovery of COOL J1241+2219, a strongly lensed galaxy at redshift z = 5.043 ± 0.002 with observed magnitude z

AB
= 20.47, lensed by a moderate-mass galaxy cluster at z = 1.001 ± 0.001. COOL J1241+2219 is the brightest lensed galaxy currently known at optical and near-infrared wavelengths at z ≳ 5; it is ∼5 times brighter than the prior record-holder lensed galaxy, and several magnitudes brighter than the brightest unlensed galaxies known at these redshifts. It was discovered as part of COOL-LAMPS, a collaboration initiated to find strongly lensed systems in recent public optical imaging data. We characterize the lensed galaxy, as well as the central galaxy of the lensing cluster using ground-based grizJH imaging and optical spectroscopy. We report model-based magnitudes, and derive stellar masses, dust content, metallicity, and star-formation rates via stellar-population synthesis modeling. Our lens mass modeling, based on ground-based imaging, implies a median source magnification of ∼30, which puts the stellar mass and star-formation rate (in the youngest age bin, closest to the epoch of observation) at logM
* =

10.11

−
0.26

+
0.21

and SFR =

27

−
9

+
13

M
⊙ yr−1, respectively. We constrain a star-formation history for COOL J1241+2219 consistent with constant star formation across ∼1 Gyr of cosmic time, and that places this galaxy on the high-mass end of the star-forming main sequence. COOL J1241+2219 is two to four times more luminous than a galaxy with the characteristic UV luminosity at these redshifts. The UV continuum slope β = −2.2 ± 0.2 places this galaxy on the blue side of the observed distribution of galaxies at z = 5, although the lack of Lyα emission indicates dust sufficient to suppress this emission.
Dynamics of Sunspot Shock Waves in the Chromosphere and Transition Region
Authors: Kayshap Pradeep , Tripathi Durgesh , Jelínek P. 
Published: January 2021

Abstract
We study the dynamics of shock waves observed in the umbra of a sunspot using the spectroscopic observations from the Interface Region Imaging Spectrograph. The presence of a shock significantly deforms the shape of the spectral lines of Mg ii, C ii, and Si iv. We found that C ii 1335.71 Å and Si iv 1393.75 Å show double-peaked profiles that change to a single peak later on. However, the Mg ii h 2803.53 Å line first shows flat-top profiles that change into double peaks followed by the single peak. To study the shock dynamics, we isolate the shock component from the spectra by fitting two Gaussians. We find that the lifetime of the shock is largest in the Mg ii h 2803.53 Å line. Moreover, the plasma motion shows both the acceleration and deceleration phases of the shock. Yet, in C ii 1335.71 Å and Si iv 1393.75 Å, only the deceleration phase is observed. We observe a strong correlation between the largest blueshift of the shock and deceleration for all three spectral lines. We find a positive (negative) correlation between intensities contributed by the shocks in Mg ii and C ii (Si iv). This suggests that the shocks are first amplified in C ii, followed by a decline in the height range corresponding to Si iv. These results may indicate the dissipation of shocks above the formation height of C ii, and the shocks may have important roles in the dynamics of the upper chromosphere and transition region above sunspots.
First Multi-redshift Limits on Post–Epoch of Reionization 21 cm Signal from z = 1.96–3.58 Using uGMRT
Authors: Chakraborty Arnab , Datta Abhirup , Roy Nirupam , Bharadwaj Somnath , Choudhury Tirthankar Roy , Datta Kanan K. , Pal Srijita , Choudhury Madhurima , Choudhuri Samir , Dutta Prasun , Sarkar Debanjan 
Published: January 2021

Abstract
Measurement of fluctuations in diffuse Hi 21 cm background radiation from the post-reionization epoch (z ≤ 6) is a promising avenue to probe the large-scale structure of the universe and understand the evolution of galaxies. We observe the European Large Area ISO Survey-North 1 (ELAIS-N1) field at 300–500 MHz using the upgraded Giant Meterwave Radio Telescope (uGMRT) and employ the “foreground avoidance” technique to estimate the Hi 21 cm power spectrum in the redshift range z = 1.96–3.58. Given the possible systematics that may remain in the data, we find the most stringent upper limits on the spherically averaged 21 cm power spectra at k ∼ 1.0 Mpc−1 are (58.87 mK)2, (61.49 mK)2, (60.89 mK)2, and (105.85 mK)2 at z = 1.96, 2.19, 2.62, and 3.58, respectively. We use this to constrain the product of neutral Hi mass density (ΩHI) and Hi bias (b
HI) to the underlying dark matter density field, [ΩHI
b
HI], as 0.09, 0.11, 0.12, and 0.24 at z = 1.96, 2.19, 2.62, and 3.58, respectively. To the best of our knowledge these are the first limits on the Hi 21 cm power spectra at the redshift range z = 1.96–3.58 and would play a significant role to constrain the models of galaxy formation and evolution.
Kepler-411 Differential Rotation from Three Transiting Planets
Authors: Araújo Alexandre , Valio Adriana 
Published: January 2021

Abstract
The differential rotation of the Sun is a crucial ingredient of the dynamo theory responsible for the generation of its magnetic field. Currently, the rotation profile of a star that hosts one or more transiting planet can be estimated. By detecting the same spot in a later transit, it is possible to infer the stellar rotation period at that latitude. In this work, we apply for the first time transit spot mapping to determine the differential rotation of Kepler-411, a K2V-type star with an average rotation period of 10.52 days, a radius of 0.79 R
⊙, and a mass of 0.83 M
⊙. Kepler-411 hosts at least four planets, the inner planet is a super-Earth with a radius of 1.88 R
⊕ and an orbital period of 3.0051 days, whereas the two larger transiting planets are mini Neptunes with radii of 3.27 and 3.31 R
⊕, and periods of 7.834435 and 58.0204 days, respectively. Their orbits are such that they transit the star at latitudes of −11°, −21°, and −49°. Analysis of the transit light curves of the three planets resulted in the detection of a total of 198 spots. For each transit latitude, the rotation period of the star was estimated and the differential rotation pattern estimated independently. Then a solar-like differential rotation profile was fit to the three rotation periods at the distinct latitudes, and the result agreed extremely well with the previous ones, resulting in a differential shear of 0.0500 ± 0.0006 rd day−1 or a relative differential rotation of 8.4% ± 0.1%.
Evidence of Increased Macroturbulence for Betelgeuse during Great Dimming
Authors: Začs Laimons , Puķı̄tis Kārlis 
Published: January 2021

Abstract
We compared high-resolution spectra of Betelgeuse observed before and during the Great Dimming. Atomic lines are shallow and broad during the Great Dimming presumably because of molecular veiling and increased macroturbulence, ν
macro ≳ 23 km s−1. The best fit for TiO bands was found for the MARCS model atmosphere with T
eff = 3500 K.
Risque d’échec entrepreneurial des PME : une explication en contexte de pays en développement
Authors: Nkakene Molou Laurence , Sangue Fotso Rober , Tchankam Jean-Paul 
Published: January 2021

Cet article examine, les facteurs explicatifs du risque d’échec entrepreneurial des PME camerounaises. Pour par venir aux résultats, nous avons effectué de prime abord une étude exploratoire auprès de huit PME des villes de Yaoundé et Douala. Cette étude exploratoire nous a permis de construire les variables contextuelles pour aboutir à un modèle d’analyse. Une enquête effectuée auprès de 152 PME camerounaises révèle que le risque d’échec de la plupart des PME provient des causes internes (notamment la mauvaise gestion financière, une main d’œuvre familiale pas toujours compétente) et des causes externes (à savoir : les non-paiements de créances, la concurrence déloyale, l’irrégularité dans l’approvisionnement en énergie électrique).
Uremia Coupled with Mucosal Damage Predisposes Mice with Kidney Disease to Systemic Infection by Commensal Candida albicans
Authors: Jawale Chetan V , Li De-Dong , Ramani Kritika , Lin Li , Li Kelvin , Methe Barbara , Biswas Partha Sarathi 
Published: January 2021

Abstract
Infections are the second major cause of mortality in patients with kidney disease and accompanying uremia. Both vascular access and non–access-related infections contribute equally to the infection-related deaths in patients with kidney disease. Dialysis is the most common cause of systemic infection by Candida albicans in these patients. C. albicans also reside in the gastrointestinal tract as a commensal fungus. However, the contribution of gut-derived C. albicans in non–access-related infections in kidney disease is unknown. Using a mouse model of kidney disease, we demonstrate that uremic animals showed increased gut barrier permeability, impaired mucosal defense, and dysbiosis. The disturbance in gut homeostasis is sufficient to drive the translocation of microbiota and intestinal pathogen Citrobacter rodentium to extraintestinal sites but not C. albicans. Interestingly, a majority of uremic animals showed fungal translocation only when the gut barrier integrity is disrupted. Our data demonstrate that uremia coupled with gut mucosal damage may aid in the translocation of C. albicans and cause systemic infection in kidney disease. Because most of the individuals with kidney disease suffer from some form of gut mucosal damage, these results have important implications in the risk stratification and control of non–access-related opportunistic fungal infections in these patients.
Comparative Valuation of Precise and Approximate Non-Linear Models of an AC Discrete Voltage Regulator and Vector Analysis of Its Parameters
Authors: Barudov Emil Stefanov , Panov Emil Ivanov 
Published: January 2021

The paper presents a review on the problems of the analysis of autotransformer discrete alternating voltage regulators. Most often the discrete regulation of AC voltages is achieved by power electronic converters based on a transformer (autotransformer) and switching by the means of controllable semiconductor switches.
The present work is dedicated to the comparison between precise and approximate non-linear models of autotransformer discrete alternating voltage regulator with changing input voltage and commutation angle of the semiconductor switches and to the vector measurements in an autotransformer discrete voltage regulator.
Design of The Position Consultative Assembly Before and After The Amandement of State Constitution of The Republic Indonesia
Authors: Putri Connie Pania , Flambonita Suci , Erniwati Erniwati , Novianti Diana 
Published: January 2021

Indonesia’s political system changed after the amandment of the state’s constitution. As a consequence, significant changes in the system are inevitable, one of which is the paradigm of its governing body. The amended constitution states that all governing bodies are level, not placing its people’s consultative assembly at the highest position of the people sovereignty manifestation at the fullest. The changes in the state’s governing bodie’s position causes transposition of their tasks and authorities. The previous assembly’s authority, bestowed by the constitution, limits itself into not having regular authority except inaugurating selected president and vice president according to the statutes of the General Election Commission once in five years. Nevertheless, a further discussion may lead to a finding that, in practice, the assembly’s authority is substantively fundamental for Indonesia’s political life. It has the right of amending and ordaining the constitution, for example, which is crucial for the politic since 1945 State Constitution of the Republic of Indonesia is the highest of all laws and regulations.
PENINGKATAN HASIL BELAJAR BAHASA INDONESIA DENGAN METODE SURVEY, QUESTION, READ, RECITE, REVIEW (SQ3R) SISWA KELAS VI DI SDN JAYABAKTI 01
Authors: NURASIAH NURASIAH 
Published: January 2021

Penelitian perbaikan pembelajaran ini bertujuan untuk meningkatkan hasil belajar siswa pada materi ciri ciri kalimat efektif pada teks melalui metode pembelajaran Survey, Question, Read, Recite, Review (SQ3R). Teknik analisis data yang digunakan dalam penelitian perbaikan pembelajaran ini yaitu data dianalisis secara kualitatif atau kuantitatif sesuai dengan jenis data yang terkumpul. Data tentang hasil belajar, yang berupa skor yang diperoleh siswa dari tes yang diberikan, dianalisis secara kuantitatif. Sementara itu, komentar observer (pengamat) terhadap kinerja guru dalam pembelajaran dianalisis secara kualitatif. Penelitian perbaikan pembelajaran ini dilakukan melalui tiga tahap, yaitu pra siklus, siklus I dan siklus II. Hasil penelitian perbaikan pembelajaran ini yaitu Penggunaan metode Survey, Question, Read, Recite, Review (SQ3R) dapat meningkatkan hasil belajar siswa materi ciri ciri kalimat efektif pada teks. Dimana pada siswa yang tuntas di pra siklus ada 27% atau 12 siswa, di siklus I meningkat menjadi 76% atau 31 siswa dan kembali meningkat di siklus II menjadi 89% atau 40 siswa yang tuntas.
PENINGKATAN KOMPETENSI PROFESIONAL GURU BIMBINGAN DAN KONSELING DALAM MENYUSUN RENCANA PELAKSANAAN LAYANAN BIMBINGAN KELOMPOK MELALUI MGMP SMPN SATU ATAP CIBITUNG KABUPATEN BEKASI
Authors: NAQIAH YAYAH DZAROTUN 
Published: January 2021

Penelitian ini bertujuan untuk mengetahui efektivitas kegiatan MGMP sekolah dalam meningkatkan kompetensi profesional guru BK dalam menyusun rencana pelaksanaan layanan bimbingan kelompok. Penelitian dilakukan terhadap guru BK SMPN Satu Atap Cibitung Kabupaten Bekasi, Jawa Barat. Penelitian ini menggunakan metode Penelitian Tindakan Sekolah . Populasi yang digunakan adalah guru BK SMPN Satu Atap Cibitung berjumlah 10 orang guru . Sampel guru yang digunakan sebanyak 3 orang guru BK yang bukan berlatar belakang BK. Instrumen utama dalam penelitian ini menggunakan teknik non tes yakni observasi, wawancara, studi dokumenter dan studi pustaka. Indikator keberhasilan guru BK adalah apabila berhasil memperoleh nilai dengan predikat baik. Nilai rata – rata yang diperoleh guru dalam menyusun RPL bimbingan kelompok pada siklus 1 sebesar 61,83 % dan siklus 2 sebesar 82,61 %. Berdasarkan hasil análisis disimpulkan bahwa MGMP Sekolah dapat meningkatkan kemampuan guru BK dalam menyusun RPL Bimbingan kelompok. Hasil Penelitian ini dapat dijadikan bahan referensi untuk meningkatkan kemampuan profesional guru . Pelaksanaan MGMP Sekolah dalam meningkatkan kompetensi profesional guru BK dapat terus dikembangkan.
Neural networks and Sigmoid Activation Function in Multi-Layer Networks
Authors: Redwan Renas M 
Published: January 2021

Back propagation neural networks are known for computing the problems that cannot easily be computed (huge datasets analysis or training) in artificial neural networks. The main idea of this paper is to implement XOR logic gate by ANNs using back propagation neural networks for back propagation of errors, and sigmoid activation function. This neural networks to map non-linear threshold gate. The non-linear used to classify binary inputs ( ) and passing it through hidden layer for computing and ( ), after computing errors by ( ) the weights and thetas ( ) are changing according to errors. Sigmoid activation function is = and Derivation of sigmoid is = . The sig(x) and Dsig(x) is between 1 to 0.
The Jake Mandell Test as a measure of individual differences in pitch discrimination: validity and reliability properties.
Authors: Olcina Sempere Gustau , Palomar-García María-Ángeles , Hernández Mireia , Parcet Ibars María Antonia , Mandell Jacob , Ávila César 
Published: January 2021

The Jake Mandell Tone Deaf Test (JMT) is an online measure designed to evaluate pitch discrimination in the normal population. The test has been available online since 2006, but no psychometric data have been published. The present research was designed to provide validity and reliability data for this test. Study 1 was conducted in university students, and the performance on the JMT was compared to the AMUSIA online screening tests. Correlations were high with the subtests of the AMUSIA online screening tests, but especially with the Tone discrimination test. Study 2 was conducted in children, and the JMT was compared to different tests of musical abilities. The JMT showed a good relationship with the Tone Discrimination and Rhythm Imitation subtest, but especially with the global score of musical abilities. In addition, the test showed good one-year test-retest reliability. Finally, external validation of the JMT was obtained by noting that musicians obtained higher scores than non-musicians. Discussion is focused on the possibility of using the JMT as a rapid screening measure of individual differences in pitch discrimination in the normal population.
Clinical, MRI, and Histopathological Features of Hypothalamic Neuronal Hamartoma in a Young Vizsla
Authors: Bibbiani Leonardo , Canal Sara , Marabese Daiana , Mandara Maria T. , Foiani Greta , Balducci Federica , Bernardini Marco 
Published: January 2021

ABSTRACT
Human hypothalamic neuronal hamartomas are rare, nonprogressive, congenital malformations of the hypothalamus that do not expand or metastasize to other locations. A 1 yr old female vizsla was presented for progressive intracranial multifocal neurological signs already present since adoption at 3 mo of age. MRI of the brain showed an ill-defined, intra-axial, space-occupying, nonenhancing lesion located in the ventral middle cranial fossa. Histopathological examination was consistent with hypothalamic neuronal hamartoma. This is the first report describing clinical, imaging, and histopathological features of a hypothalamic neuronal hamartoma in a dog. These findings are compared with the human counterparts.
β-hexanitrohexaazaisowurtzitane Particles Prepared by Spray Drying and its Characterization
Authors: XU Wenzheng , LI Hao , LIANG Xin , WANG Jie , PENG Jinyu , WANG Jingyu 
Published: January 2021

In this paper, the ultrafine β-hexanitrohexaazaisowurtzitane (β – CL – 20) particles were prepared by spray drying method. The CL – 20 samples were characterized by scanning electron microscope (SEM), particle size analyzer, X-ray diffraction (XRD), and Differential Scanning Calorimeter (DSC). Furthermore, the safety properties of samples under impact and thermal stimulus were tested and analyzed. The results of SEM showed that the average particle size of ultrafine CL – 20 particles with a narrow particle size distribution, were about 320 nm, and the shape was elliptical. The XRD patterns indicated that the polymorphic phase of ultrafine particles was mainly β-type. Compared with that of raw CL – 20, the impact sensitivity of the ultrafine CL – 20 had been decreased significantly, for the drop height (H50) was increased from 13.0 to 33.5 cm. The critical explosion temperature of the ultrafine CL – 20 decreased from 232.16 ℃ to 227.93 ℃, indicating that the thermal stability of the ultrafine CL – 20 is lower than that of raw CL – 20.
Characterization of Microstructure and Mechanical Properties of Ti-6Al-4V Alloy after Cyclic Heat Treatment
Authors: ZHANG Zhixiong , WU Ruirui , HOU Jie , WANG Tao 
Published: January 2021

A cost-effective approach which consists of cyclic heat treatment (CHT) and annealing is used to refine the coarse lamellar structure of as-cast Ti-6Al-4V alloy. The coarse lamellar microstructure was significantly refined after the CHT process, α lamellae were broken up while the original orientations of α lamellae were maintained. After annealing treatment, a basketweave microstructure was achieved in Ti-6Al-4V alloy, and the formation of globular α grains was observed. The microstructure refinement mechanisms during CHT and annealing are mainly considered to be break-up of lamellar structure and static recrystallization. The room temperature mechanical properties of Ti-6Al-4V alloy were significantly improved. The microhardness of Ti-6Al-4V alloy increased from 306 HV to 402 HV. The values of yield strength (YS) and ultimate tensile strength (UTS) increased from 734 MPa and 740 MPa to 911 MPa and 1010 MPa, respectively. The value of ductility increased from 1.1 % to 3.3 %.
An Overview of Characteristics of Clinical Next-Generation Sequencing–Based Testing for Hematologic Malignancies
Authors: Zhang Bing M. , Keegan Alissa , Li Peng , Lindeman Neal I. , Nagarajan Rakesh , Routbort Mark J. , Vasalos Patricia , Kim Annette S. , Merker Jason D. 
Published: January 2021

Context.—
With the increasing integration of molecular alterations into the evaluation of hematologic malignancies (HM), somatic mutation profiling by next-generation sequencing (NGS) has become a common clinical testing strategy. Limited data are available about the characteristics of these assays.

Objective.—
To describe assay characteristics, specimen requirements, and reporting practices for NGS-based HM testing using College of American Pathologists proficiency testing survey data.

Design.—
The College of American Pathologists NGS Hematologic Malignancies Survey (NGSHM) results from 78 laboratories were used to determine laboratory practices in NGS-based HM testing.

Results.—
The majority of laboratories performed tumor-only (88.5% [69 of 78]), targeted sequencing of cancer genes or mutation hotspots (98.7% [77 of 78]); greater than 90% performed testing on fresh bone marrow and peripheral blood. The majority of laboratories reported a 5% lower limit of detection for single-nucleotide variants (73.1% [57 of 78]) and small insertions and deletions (50.6% [39 of 77]). A majority of laboratories used benchtop sequencers and custom enrichment approaches.

Conclusions.—
This manuscript summarizes the characteristics of clinical NGS-based testing for the detection of somatic variants in HM. These data may be broadly useful to inform laboratory practice and quality management systems, regulation, and oversight of NGS testing, and precision medicine efforts using a data-driven approach.