The Hierarchical Subspace Iteration Method for Laplace–Beltrami Eigenproblems

Sparse eigenproblems are important for various applications in computer graphics. The spectrum and eigenfunctions of the Laplace–Beltrami operator, for example, are fundamental for methods in shape analysis and mesh processing. The Subspace Iteration Method is a robust solver for these problems. In practice, however, Lanczos schemes are often faster. In this article, we introduce the Hierarchical Subspace Iteration Method (HSIM) , a novel solver for sparse eigenproblems that operates on a hierarchy of nested vector spaces. The hierarchy is constructed such that on the coarsest space all eigenpairs can be computed with a dense eigensolver. HSIM uses these eigenpairs as initialization and iterates from coarse to fine over the hierarchy. On each level, subspace iterations, initialized with the solution from the previous level, are used to approximate the eigenpairs. This approach substantially reduces the number of iterations needed on the finest grid compared to the non-hierarchical Subspace Iteration Method. Our experiments show that HSIM can solve Laplace–Beltrami eigenproblems on meshes faster than state-of-the-art methods based on Lanczos iterations, preconditioned conjugate gradients, and subspace iterations.

PEMBINAAN PESERTA DIDIK DALAM IMPLEMENTASI KEBIJAKAN SISTEM ZONASI DI SMAN 1 SRENGAT

New Student Admission, hereinafter abbreviated as PPDB, is stated in the Regulation of the Minister of Education and Culture of the Republic of Indonesia Number 51 of 2018, carried out based on the principles of non-discrimination, objective, transparent, accountable and fair. One of them is implemented with the PPDB zoning system policy. The New Student Admission (PPDB) zoning system raises a number of impacts. In practice, SMAN 1 Srengat has encountered several effects that have arisen since the implementation of the PPDB zoning system. Among them are the random input of students and the low enthusiasm for learning in students who are accepted through the zoning route without any selection with qualifications based on the acquisition of learning outcomes at the previous level. This research tries to review overcoming the problems of the teaching and learning process after the implementation of the zoning system PPDB policy at SMAN 1 Srengat. So that it can be seen that, in response to the implementation of the PPDB policy of the zoning system which generates random input and raises problems in the spirit of learning, SMAN 1 Srengat implements innovation and development of transformative and comprehensive student coaching.

Матричное радиовидение на основе гетеродинного приема с применением радиолокации непрерывным излучением

A new approach to the creation of millimeter-wave radio imaging systems is proposed. This approach is based on the use of an array receiver consisting of a densely packed (pixel size - 4 mm) array of planar mixers located in the focal plane of a quasi-optical objective, with application of the frequency-modulated continuous-wave radar technique. It has been demonstrated that the implementation of the heterodyne type of reception makes it possible to increase the distance range of the array radio imaging system up to ~ 100 m while maintaining the angular resolution at the previous level.

The ‘Cruciform Test’: A diagnostic tool to detect pectoralis major rupture

Introduction Pectoralis major (PM) rupture is a severe injury that untreated can lead to a profound functional deficit. Early surgical repair can greatly improve outcomes and give a more predictable timetable for recovery, making this the goal of current treatment. Surgical intervention is also essential to return professional athletes to their previous level of competition. However, there is no single, reliable and easily reproducible test that can be used to establish the diagnosis. We describe ‘The Cruciform Test’; a method of identifying PM rupture that can be used for initial diagnosis either in clinic or a pitch-side environment, or to assess restoration of normal anatomy and function post-operatively. Methods We studied a series of 14 patients who underwent open PM repair in order to evaluate this method of assessment. Results All patients had a positive test pre-operatively. 5 were formally tested at post-operative follow-up and all had a negative result. Discussion The Cruciform Test is a simple and reproducible diagnostic tool that has potential as a clinical indicator of both PM rupture and successful repair. It can therefore contribute to earlier diagnosis, prompt surgical intervention and facilitate return to play at the earliest opportunity.

Estimation of the growth rate of wild ungulate populations in the territory of the Saratov region by the dynamic series of their numbers

The present paper is devoted to the study of the possibility of estimating the reproductive potentials of wild ungulate populations, and possibly other large mammals, by the time series of their numbers. We have found out that this is possible, which is confirmed by the high quality of approximation of the time series of abundance by logistic curves, and the corresponding coefficients of their determination for different species ranged from 75 to 96%. For such calculations, one circumstance is necessary, which is that the population of the studied species has been briefly exposed to some unfavorable factor causing a significant reduction in its numbers with subsequent restoration to the previous level, or the time series should contain a well-expressed and extended section of the transition of the population from some lower level to the upper level of the population, passing into a stationary state. The values of the maximum exponential growth rates of ungulate populations that we obtained do not fundamentally differ from the data available in other researchers’ works. In addition, it should be borne in mind that our method for assessing the reproductive potentials of ungulates is statistical, with features accompanying all such methods, for example, in the presence of statistical errors in all determined parameters. However, the evaluation of the magnitude of these errors is a topic for a separate study.

Deep Digital Flexor Tendon Injury at the Level of the Proximal Phalanx in Frontlimbs With Tendon Sheath Distension Characterized by Standing Low-Field Magnetic Resonance Imaging in Horses: 13 Cases (2015–2021)

Objective: To describe the MRI findings for 13 horses with deep digital flexor tendon (DDFT) injury at the proximal phalanx where the tendon goes from ovoid to bilobed in frontlimbs with tendon sheath distension. In addition, the prognosis of this lesion was assessed.Design: Retrospective case series.Animals: Thirteen client-owned horses.Procedures: Medical records were reviewed, and data were collected regarding signalment, history, MRI findings, and outcomes of horses. Findings of MRI were recorded and whether the case was confirmed with tenoscopy.Results: A diagnosis of DDFT injury at the junction between ovoid and bilobed portions at the level of the proximal phalanx was established in 13/20 (65%) horses that underwent MRI examination of the frontlimb digital flexor tendon sheath. Return to previous level of work was poor in this subset of horses with only three of 13 (23%) horses returning to previous level of work and one horse still in rehabilitation.Conclusions and Clinical Relevance: Standing low-field MRI represents a potentially useful diagnostic tool to evaluate digital flexor tendon sheath distension especially when evaluating the DDFT at the proximal phalanx where the tendon progresses from ovoid to bilobed. Prognosis of lesions of the DDFT at the proximal phalanx appears less favorable than previously reported causes of tendon sheath distension.

Zirconia in the Service of Anterior Aesthetic Restorations

Introduction: Zirconia appears in odontology fifteen years ago under the form of a screed covered with feldspathic ceramic, as an alternative to the ceramic-metal crown. The success of zirconia stems from its biocompatibility and aesthetic potential in combination with optimized mechanical properties. For years, zirconia was the benchmark for the restoration of the posterior sector. Today translucent zirconia are offered to satisfy aesthetic demands even at the previous level Observation: The 54-year-old HA patient consulted for the replacement of her old ceramic-metal bridge in the anterior sector. Its motif was both aesthetic and functional. The therapeutic choice was directed towards the creation of metal ceramic bridge with a zirconia coping. The clinical steps necessary for this prosthetic design will be detailed step by step. Discussion: Several ceramics are now available to us for aesthetic anterior restorations. However, the choice of the appropriate ceramic is not only guided by aesthetic needs. Other parameters must be taken into consideration such as the situation of the finish line, the height of the stumps ... Zirconia may not seem like the ideal ceramic for anterior restorations. However, when the case requires, we can opt for an "improved" zirconia giving wide aesthetic satisfaction Key words: zirconia, aesthetics, translucency, opacity, density.

Association of the Psychological Response to the ACL-SPORTS Training Program and Self-reported Function at 2 Years After Anterior Cruciate Ligament Reconstruction

Background: Psychological readiness to return to sport has emerged as an important factor associated with outcomes after anterior cruciate ligament reconstruction (ACLR). Psychological factors are potentially modifiable during the course of rehabilitation, and improving them may lead to better outcomes. Purpose: To determine whether athletes with a positive psychological response after participation in a neuromuscular training and second injury prevention program had better self-reported function and activity outcomes compared with athletes who did not have a meaningful change. Study Design: Cohort study; Level of evidence, 3. Methods: After ACLR and the completion of formal rehabilitation, 66 level I/II athletes completed the following self-reported measures at enrollment (pretraining): the Anterior Cruciate Ligament–Return to Sport after Injury (ACL-RSI) scale, the International Knee Documentation Committee (IKDC) subjective knee form, and the 5 subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS). Participants completed these measures after 10 sessions of agility, plyometric, and progressive strength training and at 1 and 2 years after ACLR. Participants who displayed an increase in the ACL-RSI score from pretraining to posttraining that exceeded the minimal clinically important difference (≥10 points) were defined as having a positive psychological response (responders) to training, and those who did not were defined as nonresponders. A mixed-model analysis of variance was used to determine if group differences in IKDC and KOOS scores existed over the 4 time points (pretraining, posttraining, and the 1- and 2-year follow-ups). Results: The responders reported better self-reported function compared with the nonresponders, regardless of time, on the IKDC form ( P = .001), KOOS–Sport and Recreation ( P = .014), KOOS-Pain ( P = .007), and KOOS-Symptoms ( P = .002) but not on the KOOS–Quality of Life ( P = .078). Overall, 77% of responders and 67% of nonresponders returned to their previous level of sport by 1 year after ACLR ( P = .358), and 82% of responders and 78% of nonresponders returned to their previous level of sport by 2 years after ACLR ( P = .668). Conclusion: Ultimately, 59% of the athletes in this study displayed a meaningful improvement in their psychological outlook over the course of the training program. Responders demonstrated persistently better self-reported function at posttraining and at 1 and 2 years after ACLR, but there were no between-group differences in return-to-sport rates.

The Injured Shoulder in High-Level Male Gymnasts, Part 2: Can Athletes Return to Competition After Surgery?

Background: The results of surgical treatment of shoulder injuries in high-level male gymnasts have not yet been documented. Purpose: To evaluate the functional and subjective results after surgical treatment of shoulder injuries in high-level gymnasts and the possibilities to return to sport at the same level. Study Design: Case series; Level of evidence, 4. Methods: Over a 20-year period (1994-2014), 23 high-level male gymnasts (26 shoulders) underwent surgery by a single experienced shoulder surgeon. At the time of surgery, 7 gymnasts competed at the international level, 12 at the national elite level, and 4 at the regional level. According to symptoms and anatomic lesions, the shoulders were classified into 2 groups: painful shoulders (n = 11) and unstable shoulders (n = 15). Fifteen capsulolabral repairs, 10 cuff debridements, 1 cuff repair, 4 SLAP (superior labral anterior and posterior) repairs, and 8 suprapectoral biceps tenodesis were performed. Twelve shoulders (46%) had >1 procedure performed. Outcomes assessment was performed by an independent observer at a mean of 5 years (range, 2-15 years) postoperatively. In addition, patients completed the Subjective Shoulder Value (range, 0%-100%). Results: After shoulder surgery, 21 (91%) of the 23 gymnasts returned to competitive gymnastics, and 20 gymnasts (87%) regained their preinjury level of sport. All international-level gymnasts returned to their preinjury level of sport. Three athletes (13%) underwent revision surgery, and 1 athlete (4%) ended his career without returning to competition. The postoperative period before resumption of competitive gymnastics was 9 ± 3.5 months (mean ± SD). Of the 15 gymnasts treated for shoulder instability with arthroscopic stabilization, 12 were able to return to their previous level of sport. All 8 gymnasts who had arthroscopic biceps tenodesis were able to return to their previous level of sport, as opposed to only 2 of 4 gymnasts treated with SLAP repair. The gymnastics-specific Subjective Shoulder Value score was 80% ± 11%. Conclusion: Most gymnasts who required surgical treatment for a shoulder injury were able to return to competition at their previous level, although there was a considerable postoperative recovery period. Current arthroscopic reconstruction techniques were effective for treating structural lesions and allowing return to high-level gymnastics.

Affective polarization in the digital age: Testing the direction of the relationship between social media and users’ feelings for out-group parties

There is considerable disagreement among scholars as to whether social media fuels polarization in society. However, a few have considered the possibility that polarization may instead affect social media usage. To address this gap, the study uses Dutch panel data to test directionality in the relationship between social media use and affective polarization. No support was found for the hypothesis that social media use contributed to the level of affective polarization. Instead, the results lend support to the hypothesis that it was the level of affective polarization that affected subsequent use of social media. The results furthermore reveal heterogeneous patterns among individuals, depending on their previous level of social media usage, and across different social media platforms. The study gives reason to call into question the predominating assumption in previous research that social media is a major driver of polarization in society.