bluuebunny/crossref_metadata_2025_split huggingface dataset:
LAWS OF MOTION IN THE FRAME THEORIES OF GRAVITY
Authors: Samokhvalov S. 
Published: April 2021

One of the most striking features of the general relativity (GR) is the fact that the matter that generates gravitational field cannot move arbitrarily, but must obey certain equations that follow from equations of the gravitational field as a condition of their compatibility. This fact was first noted in the fundamental Hilbert's work, in which equations of GR saw the world for the first time as variational Lagrange equations. Hilbert showed that in the case when fulfilling equations of the gravitational field which were born by an electromagnetic field, four linear combinations of equations of the electromagnetic field and their derivatives are zero due to the general covariance of the theory. It is known that this is what stimulated E. Noether to invent her famous theorem.
As for "solid matter", for the compatibility of equations of the gravitational field, it is necessary that particles of dust matter move along geodesics of Riemannian space, which describes the gravitational field. This fact was pointed out in the work of A. Einstein and J. Grommer and according to V. Fock it is one of the main justifications of GR (although even before the creation of GR it was known that the motion along geodesics is a consequence of the condition of covariant conservation of energy-momentum of matter). This remarkable feature of GR all his life inspired Einstein to search on the basis of GR such theory from which it would be possible to derive all fundamental physics, including quantum mechanics.
Interest in this problem (following Einstein, we name it the problem of motion) has resumed in our time in connection with the registration of gravitational waves and analysis of the conditions of their radiation, i.e. the need for its direct application in gravitational-wave astronomy.
In this article we consider the problem to what extent the motion of matter that generates the gravitational field can be arbitrary. Considered problem is analyzed from the point of view symmetry of the theory with respect to the generalized gauge deformed groups without specification of Lagrangians.
In particular it is shown, that the motion of particles along geodesics of Riemannian space is inherent in an extremely wide range of theories of gravity and is a consequence of the gauge translational invariance of these theories under the condition of fulfilling equations of gravitational field. In addition, we found relationships of equations for some fields that follow from the assumption about fulfilling of equations for other fields, for example, relationships of equations of the gravitational field which follow from the assumption about fulfilling of equations of matter fields.
Reasons for revision following stand-alone anterior lumbar interbody fusion and lateral lumbar interbody fusion
Authors: Nguyen Austin Q. , Harvey Jackson P. , Khanna Krishn , Basques Bryce A. , Harada Garrett K. , Phillips Frank M. , Singh Kern , Dewald Christopher , An Howard S. , Colman Matthew W 
Published: April 2021

OBJECTIVE
Anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) are alternative and less invasive techniques to stabilize the spine and indirectly decompress the neural elements compared with open posterior approaches. While reoperation rates have been described for open posterior lumbar surgery, there are sparse data on reoperation rates following these less invasive procedures without direct posterior decompression. This study aimed to evaluate the overall rate, cause, and timing of reoperation procedures following anterior or lateral lumbar interbody fusions without direct posterior decompression.

METHODS
This was a retrospective cohort study of all consecutive patients indicated for an ALIF or LLIF for lumbar spine at a single academic institution. Patients who underwent concomitant posterior fusion or direct decompression surgeries were excluded. Rates, causes, and timing of reoperations were analyzed. Patients who underwent a revision decompression were matched with patients who did not require a reoperation, and preoperative imaging characteristics were analyzed to assess for risk factors for the reoperation.

RESULTS
The study cohort consisted of 529 patients with an average follow-up of 2.37 years; 40.3% (213/529) and 67.3% (356/529) of patients had a minimum of 2 years and 1 year of follow-up, respectively. The total revision rate was 5.7% (30/529), with same-level revision in 3.8% (20/529) and adjacent-level revision in 1.9% (10/529) of patients. Same-level revision patients had significantly shorter time to revision (7.14 months) than adjacent-level revision patients (31.91 months) (p < 0.0001). Fifty percent of same-level revisions were for a posterior decompression. After further analysis of decompression revisions, an increased preoperative canal area was significantly associated with a lower risk of further decompression revision compared to the control group (p = 0.015; OR 0.977, 95% CI 0.959–0.995).

CONCLUSIONS
There was a low reoperation rate after anterior or lateral lumbar interbody fusions without direct posterior decompression. The majority of same-level reoperations were due to a need for further decompression. Smaller preoperative canal diameters were associated with the need for revision decompression.
Complications in ambulatory pediatric patients with nonidiopathic spinal deformity undergoing fusion to the pelvis using the sacral-alar-iliac technique within 2 years of surgery
Authors: Menger Richard , Park Paul J. , Bixby Elise C. , Marciano Gerard , Cerpa Meghan , Roye David , Roye Benjamin D. , Vitale Michael , Lenke Lawrence 
Published: April 2021

OBJECTIVE
Significant investigation in the adult population has generated a body of research regarding proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) following long fusions to the sacrum and pelvis. However, much less is known regarding early complications, including PJK and PJF, in the ambulatory pediatric patient. As such, the objective of this study was to address the minimal literature on early complications after ambulatory pediatric patients underwent fusion to the sacrum with instrumentation to the pelvis in the era of sacral-alar-iliac (S2AI) instrumentation.

METHODS
The authors performed a retrospective review of pediatric patients with nonidiopathic spinal deformity < 18 years of age with ambulatory capacity who underwent fusion to the pelvis at a multisurgeon pediatric academic spine practice from 2016 to 2018. All surgeries were posterior-only approaches with S2AI screws as the primary technique for sacropelvic fixation. Descriptive, outcome, and radiographic data were obtained. The definition of PJF included symptomatic PJK presenting as fracture, screw pullout, or disruption of the posterior osseoligamentous complex.

RESULTS
Twenty-five patients were included in this study. Nine patients (36.0%) had 15 complications for an overall complication rate of 60.0%. Unplanned return to the operating room occurred 8 times in 6 patients (24.0%). Four patients (16.0%) had wound issues (3 with deep wound infection and 1 with wound breakdown) requiring reoperation. Three patients (12.0%) had PJF, all requiring reoperation. A 16-year-old female patient with syndromic scoliosis underwent extension of fusion due to posterior tension band failure at 6 months. A 17-year-old male patient with neuromuscular scoliosis underwent extension of fusion due to proximal screw pullout at 5 months. A 10-year-old female patient with congenital scoliosis underwent extension for PJF at 5 months following posterior tension band failure. One patient had pseudarthrosis requiring reoperation 20 months postoperatively.

CONCLUSIONS
Fixation to the pelvis enables significant deformity correction, but with rather high rates of complications and unexpected returns to the operating room. Considerations of sagittal plane dynamics for PJK and PJF should be strongly analyzed when performing fixation to the pelvis in ambulatory pediatric patients.
Comparison of operator and patient radiation exposure during fluoroscopy-guided vertebroplasty and kyphoplasty: a systematic review and meta-analysis
Authors: Kopparapu Srujan , Lubelski Daniel , Pennington Zach , Khan Majid , Theodore Nicholas , Sciubba Daniel 
Published: April 2021

OBJECTIVE
Percutaneous vertebroplasty (PV) and balloon kyphoplasty (BK) are two minimally invasive techniques used to treat mechanical pain secondary to spinal compression fractures. A concern for both procedures is the radiation exposure incurred by both operators and patients. The authors conducted a systematic review of the available literature to examine differences in interventionalist radiation exposure between PV and BK and differences in patient radiation exposure between PV and BK.

METHODS
The authors conducted a search of the PubMed, Ovid Medline, Cochrane Reviews, Embase, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Full-text articles in English describing one of the primary endpoints in ≥ 5 unique patients treated with PV or BK of the mobile spine were included. Estimates of mean operative time, radiation exposure, and fluoroscopy duration were reported as weighted averages. Additionally, annual occupational dose limits provided by the United States Nuclear Regulatory Commission (USNRC) were used to determine the number needed to harm (NNH).

RESULTS
The meta-analysis included 27 articles. For PV, the mean fluoroscopy times were 4.9 ± 3.3 minutes per level without protective measures and 5.2 ± 3.4 minutes with protective measures. The mean operator radiation exposures per level in mrem were 4.6 ± 5.4 at the eye, 7.8 ± 8.7 at the neck, 22.7 ± 62.4 at the torso, and 49.2 ± 62.2 at the hand without protective equipment and 0.3 ± 0.1 at the torso and 95.5 ± 162.5 at the hand with protection. The mean fluoroscopy times per level for BK were 6.1 ± 2.5 minutes without protective measures and 6.0 ± 3.2 minutes with such measures. The mean exposures were 31.3 ± 39.3, 19.7 ± 4.6, 31.8 ± 34.2, and 174.4 ± 117.3 mrem at the eye, neck, torso, and hand, respectively, without protection, and 1, 9.2 ± 26.2, and 187.7 ± 100.4 mrem at the neck, torso, and hand, respectively, with protective equipment. For protected procedures, radiation to the hand was the limiting factor and the NNH estimates were 524 ± 891 and 266 ± 142 for PV and BK, respectively. Patient exposure as measured by flank-mounted dosimeters, entrance skin dose, and dose area product demonstrated lower exposure with PV than BK (p < 0.01).

CONCLUSIONS
Operator radiation exposure is significantly decreased by the use of protective equipment. Radiation exposure to both the operator and patient is lower for PV than BK. NNH estimates suggest that radiation to the hand limits the number of procedures an operator can safely perform. In particular, radiation to the hand limits PV to 524 and BK to 266 procedures per year before surpassing the threshold set by the USNRC.
Pengaruh Intellectual Capital Terhadap Kinerja Keuangan dan Nilai Perusahaan (Studi Kasus Perusahaan Sektor Keuangan yang Terdaftar di Bursa Efek Indonesia Tahun 2017-2019)
Authors: Rahmadi Ikhram Hafiz , Mutasowifin Ali 
Published: April 2021

Berlainan dengan asset tradisional yang berwujud, intellectual capital merupakan hidden value yang kurang memperoleh perhatian. Penelitian ini menguji pengaruh intellectual capital terhadap kinerja keuangan dan nilai perusahaan. Penelitian ini menggunakan metode value added intellectual coefficient (VAIC) sebagai indikator untuk menghitung nilai intellectual capital perusahaan. Kinerja keuangan diukur oleh empat indikator yaitu Return on Assets (ROA), Return on Equity (ROE), Debt to Assets (DAR) dan Debt to Equity (DER). Nilai Perusahaan diukur oleh indikator Earning per Share (EPS), Price to Earning Ratio (PER), Price to Book Value Ratio (PBV), dan Tobin’s Q. Penelitian ini menggunakan alat analisis Partial Least Square (PLS) dengan memanfaatkan aplikasi SmartPLS versi 3.2.2. Sampel dalam penelitian ini adalah perusahaan sektor keuangan pada Bursa Efek Indonesia pada 2017-2019. Hasil penelitian menunjukan bahwa terdapat pengaruh positif dan signifikan antara Intellectual Capital terhadap Kinerja Keuangan dan Nilai perusahaan.
PENANAMAN KARAKTER KEBANGSAAN MELALUI PEMBELAJARAN BERBASIS KEARIFAN LOKAL DI SEKOLAH DASAR
Authors: Awang Imanuel Sairo , Serani Gabriel , Prasetyo Zuhdan Kun , Wangid Muhammad Nur 
Published: April 2021

ABSTRAKDewasa ini peserta didik tidak hanya dituntut menguasai ketiga ranah hasil belajar yaitu kognitif, afektif, dan psikomotor, tetapi juga meliputi pengembangan karakter yang dapat diintegrasikan melalui kearifan lokal. Penelitian ini bertujuan untuk menghasilkan perangkat pembelajaran berbasis kearifan lokal di sekolah dasar. Penelitian ini merupakan penelitian Research and Development (R&D) model 4D yakni define, design, develop, dan disseminate. Subjek ujicoba penelitian adalah siswa kelas III SD Negeri 12 Ensaid Panjang. Instrument pengumpulan data dalam penelitian ini adalah lembar validasi produk, lembar observasi, dan lembar tes hasil belajar. Teknik anaslis data yang digunakan adalah kualitatif deskriptif. Hasil penelitian menunjukkan bahwa perangkat pembelajaran yang terdiri dari silabus, Rencana Pelaksanaan Pembelajaran (RPP), Lembar Kerja Peserta Didik (LKPD), dan lembar penilaian, valid berkategori “baik” dan dinyatakan layak untuk diterapkan. Hasil ujicoba menunjukkan bahwa perangkat pembelajaran berbasis kearifan lokal mampu meningkatkan karakter kebangsaan kejujuran, persatuan, dan gotong-royong masing-masing sebesar 0,08, 0,16 dan 0,07. Hasil tes juga menunjukkan bahwa perangkat pembelajaran berbasis kearifan lokal suku Dayak Desa mampu mengembangkan hasil belajar peserta didik yakni sebesar 74,38. Dengan demikian, pembelajaran berbasis kearifan lokal dapat menanamkan karakter kebangsaan peserta didik sekolah dasar.Kata Kunci: Perangkat pembelajaran, kearifan lokal, karakter kebangsaan ABSTRACTNowadays students are not only required to master the three domains of learning outcomes, namely cognitive, affective, and psychomotor, but also include character development that can be integrated through local wisdom. This study aims to produce learning kits based on local wisdom in elementary schools. This research conducted with Research and Development (R&D) within 4D stages model i.e define, design, develop, and disseminate. The subjects of the research trial were grade III students of SD Negeri 12 Ensaid Panjang. Data collection instruments in this study were product validation sheets, observation sheets, and learning achievement test sheets. The data analysis technique used is descriptive qualitative. The results showed that the learning kit consisting of syllabus, lesson plan, student worksheet, and assessment sheet, was valid in the category of "good" and declared feasible to be applied. The results show that the learning kits based on local wisdom can improve the national character of honesty, unity, and mutual assistance respectively by 0.08, 0.16, and 0.07. The test results also showed that the local wisdom-based learning tools of the Dayak Desa tribe were able to develop student learning outcomes, with score 74.38. Thus, learning kits based on local wisdom can instill the national character of elementary school students.Keywords: Learning kits, local wisdom, nationality character
Penerapan Model STAD dalam Meningkatkan Hasil Belajar Pendidikan Agama Katolik Siswa SMK Negeri 5 Manado
Authors: Sili Fransiskus 
Published: April 2021

ABSTRAKTujuan penelitian ini adalah meningkatkan hasil belajar pada mata pelajaran Pendidikan Agama Katolik siswa kelas X SMK Negeri 5 Manado melalui penerapan model Cooperative Learning tipe STAD. Penelitian ini menggunakan desain penelitian tindakan kelas dengan pelaksanaan pembelajaran sebanyak dua siklus. Subjek penelitian adalah siswa kelas X SMK Negeri 5 Manado yang berjumlah 17 siswa. Analisis data menggunakan analisis interaktif model Milles dan Huberman. Hasil penelitian menunjukkan bahwa rerata skor tes siklus I adalah 74,89 dan rerata aktivitas adalah 74.95%. Pada siklus ke II mengalami peningkatan skor rerata nilai siswa yakni 85,22 dengan kategori sangat baik, dan rerata persentase aktivitas belajar siswa adalah 88.61% masuk kategori sangat baik. Dapat disimpulkan bahwa penerapan model Cooperative Learning tipe STAD telah meningkatkan hasil belajar siswa pada mata pelajaran Pendidikan Agama Katolik dengan rerata skor tingkat ketuntasan adalah 75. Untuk meningkatkan efisiensi penerapan model STAD dalam pelajaran pendidikan agama Katolik maka guru perlu memperkuat kemampuan manajerial kelompok sera meningkatkan dinamika diskusi kelompok untuk memobilisasi kekuatan individual team yang heterogen di kelas pembelajaran Pendidikan Agama Katolik.Kata Kunci: hasil belajar, model STAD ABSTRACTThis classroom action research is designed to enhance the academic achievement in Catholic Religious Education class by applying cooperative learning type STAD (Students Teams Achievement Divisions). The research subjects were 17 students of grade X in SMK Negeri 5 Manado. Data analysis in two cycles of learning shows the following results. The first learning cycle average test score was 74.89 and the mean activity was 74.95%. The second learning cycle average test was 85.22 (very good category) and the average percentage of student learning activities was 88.61% (very good category). It can be concluded that the application of the STAD Cooperative Learning model has improved academic achievement with an average score of completeness level is 75. To increase the efficiency of the application of the STAD model, teachers need to strengthen group managerial abilities and increase the dynamics of group discussions to mobilize the strength of heterogeneous individual teams in the Catholic Religious Education class.Keywords: learning outcomes, STAD models
EVALUASI PELAKSANAAN PEMBELAJARAN DARING DI INDONESIA SELAMA MASA PANDEMI COVID-19
Authors: Budiman Jumardi 
Published: April 2021

ABSTRAKPandemi covid-19 membuat sistem pembelajaran di Indonesia yang berlangsung secara klasikal berubah menjadi pembelajaran dalam jaringan (daring). Tujuan penelitian ini yakni mengevaluasi pelaksanaan pembelajaran daring di Indonesia pada masa pandemi covid-19. Metode penelitian menggunakan studi kepustakaan dengan sumber data berupa artikel ilmiah yang membahas tentang pelaksanaan pembelajaran daring selama masa pandemi covid-19. Teknik analisis data menggunakan analisa kualitatif yakni reduksi data, penyajian data dan verifikasi/ penarikan kesimpulan. Temuan dalam penelitian ini bahwa mekanisme pembelajaran daring memiliki dampak positif berupa kemandirian siswa dalam belajar, peningkatan aktivitas mencari sumber belajar dan inovasi gaya belajar. Dampak negatif pembelajaran daring berupa rasa jenuh dan penurunan minat belajar akibat kegagalan siswa dan guru dalam mengatasi kendala seperti sarana penunjang yang tidak memadai, ketiadaan kuota internet dan sinyal internet yang buruk. Tantangan yang dihadapi oleh siswa dan guru selama pembelajaran daring yakni ketersediaan sarana penunjang, strategi pembelajaran yang inovatif dan sinergi ntara komponen pendidikan. Pembelajaran daring berpeluang untuk terus dilaksanakan dengan system blended learning guna menciptakan ekosistem pembelajaran digital yang efektif dan efisien.Kata Kunci: Evaluasi, pembelajaran, dalam jaringan, pandemi covid-19 ABSTRACTPandemic covid-19 makes the learning system in Indonesia that takes place classically turned into online learning. The purpose of this study is to evaluate the implementation of online learning in Indonesia during the Covid-19 pandemic. The research method uses library research with data sources in the form of scientific articles that discuss the implementation of online learning during the Covid-19 pandemic. The data analysis technique uses qualitative analysis, namely data reduction, data presentation and verification / conclusion. The findings in this study are that online learning mechanisms have a positive impact in the form of student’s independence in learning, increased activity to find learning resources and innovation in learning styles. The negative impact of online learning is in the form of boredom and decreased interest in learning due to the failure of students and teachers to overcome obstacles such as inadequate supporting facilities, absence of internet quota and poor internet signal. The challenges faced by students and teachers during online learning are the availability of supporting facilities, innovative learning strategies and synergy between education components. Online learning has the opportunity to continue to be implemented with a blended learning system to create an effective and efficient digital learning ecosystemKeywords: Evaluation, learning, online, the covid-19 pandemic
ANALISIS PROFIL PERSEPSI DAN MOTIVASI BELAJAR DARING SISWA SMK DI KOTA SINGARAJA
Authors: Fitria Ida , Candiasa I Made , Sugiarta I Made 
Published: April 2021

ABSTRAKSejak Maret 2020 diterapkan sistem belajar daring. Pengkajian persepsi siswa terhadap belajar daring diperlukan untuk mengetahui tanggapan siswa sehingga tercipta pembelajaran yang bermakna. Belajar daring dilakukan tanpa tatap muka juga perlu dikaji mengenai motivasi belajar siswa untuk mencapai tujuan pembelajaran. Tujuan penelitian adalah untuk mengetahui kedudukan persepsi dan motivasi siswa selama belajar daring sehingga hasilnya bisa dipergunakan untuk perencanaan pembelajaran kedepannya. Pengumpulan data menggunakan data sekunder dari peneliti utama berupa data pengukuran persepsi dan motivasi siswa belajar daring yang diperoleh dari hasil tiga kali pengukuran selama empat minggu dilakukan pembelajaran daring, yakni pengukuran awal setelah dua minggu, dan setelah empat minggu. Analisis data pada penelitian ini adalah analisis profil dengan tiga pengujian hipotesis yaitu uji hipotesis keparalelan, uji hipotesis kesamaan level dan uji hipotesis untuk pengaruh pvariabel utama. Berdasarkan hasil analisis data dapat disimpulkan, kedua pengukuran persepsi dan motivasi paralel, berbeda level, dan ada pengaruh terhadap 3 variabel.Kata Kunci : analisis profil, persepsi, motivasi ABSTRACTSince March 2020 an online learning system has been implemented. Students' perceptions of online learning need to be researched so that meaningful learning is created. Student learning motivation also needs to be studied because learning is not face to face. The research objective was to determine the position of students' perceptions and motivation during online learning so that the results could be used for planning future learning. The data collection used secondary data from the main researcher in the form of online learning students' perceptions and motivation measurement data obtained from the results of three measurements for four weeks. The data analysis in this study is a profile analysis. Based on the results of the data analysis, it can be concluded that the two measurements of perception and motivation are parallel, have different levels, and there is an influence on 3 variables.Keywords : profile analysis, perception, motivation