3DMesh-GAR: 3D Human Body Mesh-Based Method for Group Activity Recognition.

Group activity recognition is a prime research topic in video understanding and has many practical applications, such as crowd behavior monitoring, video surveillance, etc. To understand the multi-person/group action, the model should not only identify the individual person's action in the context but also describe their collective activity. A lot of previous works adopt skeleton-based approaches with graph convolutional networks for group activity recognition. However, these approaches are subject to limitation in scalability, robustness, and interoperability. In this paper, we propose 3DMesh-GAR, a novel approach to 3D human body Mesh-based Group Activity Recognition, which relies on a body center heatmap, camera map, and mesh parameter map instead of the complex and noisy 3D skeleton of each person of the input frames. We adopt a 3D mesh creation method, which is conceptually simple, single-stage, and bounding box free, and is able to handle highly occluded and multi-person scenes without any additional computational cost. We implement 3DMesh-GAR on a standard group activity dataset: the Collective Activity Dataset, and achieve state-of-the-art performance for group activity recognition.

Trophic response to ecological conditions of habitats: Evidence from trophic variability of freshwater fish.

To adapt to ecological and environmental conditions, species can change their ecological niche (e.g., interactions among species) and function (e.g., prey-predation, diet competition, and habitat segregation) at the species and guild levels. Stable isotope analysis of bulk carbon and nitrogen of organisms has conventionally been used to evaluate such adaptabilities in the scenopoetic and bionomic views as the isotopic niche width.Compound-specific stable isotope analysis (CSIA) of nitrogen within amino acids provides trophic information without any disruption of scenopoetic views in the isotope ratios, unlike conventional bulk isotope analysis provides both information and therefore frequently hinders its usefulness for trophic information.We performed CSIA of amino acids to understand the trophic variability of the pike gudgeon Pseudogobio esocinus and largemouth bass Micropterus salmoides as representative specialist and generalist fish species, respectively, from 16 ecologically variable habitats in the four major rivers of Korea.There was little variation (1σ) in the trophic position (TP) among habitats for P. esocinus (± 0.2); however, there was considerably large variation for M. salmoides (± 0.6). The TP of M. salmoides was negatively correlated with the benthic invertebrate indices of the habitats, whereas the TP of P. esocinus showed no significant correlation with any indices. Thus, these two representative fish species have different trophic responses to ecological conditions, which is related to known differences in the trophic niche between specialists (i.e., small niche width) and generalists (i.e., large niche width).Over the past four decades, the conventional bulk isotope analysis has not been capable of deconvoluting "scenopoetic" and "bionomic" information. However, in the present study, we demonstrated that the CSIA of amino acids could isolate trophic niches from the traditional ecological niche composed of trophic and habitat information and evaluated how biological and ecological indices influence the trophic response of specialists and generalists.

Patient-specific Guides Using 3-dimensional Reconstruction Provide Accuracy and Reproducibility in Reverse Total Shoulder Arthroplasty.

BACKGROUND: We aimed to evaluate whether the use of our novel patient-specific guide (PSG) with 3-dimensional reconstruction in reverse total shoulder arthroplasty (RTSA) would allow accurate and reliable implantation of the glenoid and humeral components. METHODS: 20 fresh-frozen cadaveric shoulders were used. The PSG group (n=10) and conventional group (n=10) was evaluated the accuracy and reproducibility of implant positioning between before and after surgery on the computed tomography image. RESULTS: The superoinferior and anteroposterior offset in the glenoid component were 0.42 ± 0.07, 0.50 ± 0.08 in the conventional group and 0.45 ± 0.03, 0.46 ± 0.02 in the PSG group. The inclination and version angles were -1.93° ± 4.31°, 2.27° ± 5.91° and 0.46° ± 0.02°, 3.38° ± 2.79°. The standard deviation showed a smaller difference in the PSG group. The anteroposterior and lateromedial humeral canal center offset in the humeral component were 0.45 ± 0.12, 0.48 ± 0.15 in the conventional group and 0.46 ± 0.59 (p=0.794), 0.46 ± 0.06 (p=0.702) in the PSG group. The PSG showed significantly better humeral stem alignment. CONCLUSIONS: The use of PSGs with 3-dimensional reconstruction reduces variabilities in glenoid and humerus component positions and prevents extreme positioning errors in RTSA.

Sustained Delivery of Transforming Growth Factor ß1 by Use of Absorbable Alginate Scaffold Enhances Rotator Cuff Healing in a Rabbit Model.

BACKGROUND: The failure rate for healing after rotator cuff repair is relatively high. PURPOSE: To establish a system for sustained release of transforming growth factor ß1 (TGF-ß1) using an alginate scaffold and evaluate the effects of the sustained release of TGF-ß1 on rotator cuff healing in a rabbit model. STUDY DESIGN: Controlled laboratory study. METHODS: Before the in vivo animal study, a standard MTS assay was performed to evaluate cell proliferation and metabolic activity on the alginate scaffold. Additionally, an enzyme-linked immunosorbent assay was performed to confirm the capacity of the sustained release of TGF-ß1-containing alginate scaffold. Once the in vitro studies were completed, bilateral supraspinatus tendon repairs were performed in 48 rabbits that were allocated to 3 groups (n = 16 each) (group 1, supraspinatus repair only; group 2, supraspinatus repair with TGF-ß1 single injection; group 3, supraspinatus repair with TGF-ß1 sustained release via an alginate-based delivery system). Biomechanical and histological analyses were performed to evaluate the quality of tendon-to-bone healing at 12 weeks after rotator cuff repair. RESULTS: The cell proliferation rate of the alginate scaffold was 122.30% compared with the control (fresh medium) group, which confirmed that the alginate sheet had no cytotoxicity and enhanced cell proliferation. Additionally, the level of TGF-ß1 was found to increase with time on the alginate scaffold. Biomechanically, group 3 exhibited a significantly heightened ultimate failure load compared with groups 1 and 2 (group 1, 74.89 ± 29.82 N; group 2, 80.02 ± 34.42 N; group 3, 108.32 ± 32.48 N; P = .011) and more prevalent midsubstance tear compared with group 1 ( P = .028). However, no statistical differences were found in the cross-sectional area of the supraspinatus tendon (group 1, 32.74 ± 9.38; group 2, 33.76 ± 8.89; group 3, 34.80 ± 14.52; P = .882) and ultimate stress (group 1, 2.62 ± 1.13 MPa; group 2, 2.99 ± 1.81 MPa; group 3, 3.62 ± 2.24 MPa; P = .317). Histologically, group 3 exhibited a significantly heightened modified total Bonar score (group 1, 5.00 ± 1.54; group 2, 6.12 ± 1.85; group 3, 7.50 ± 1.31; P = .001). In addition, the tendon-to-bone interface for group 3 demonstrated better collagen orientation, continuity, and organization, and the area of new fibrocartilage formation was more evident in group 3. CONCLUSION: At 12 weeks after rotator cuff repair, the authors found improved biomechanical and histological outcomes for sustained release of TGF-ß1 using alginate scaffold in a rabbit model. CLINICAL RELEVANCE: The alginate-bound growth factor delivery system might improve healing after rotator cuff repair in humans.

Occipitocervical inclination: new radiographic parameter of neutral occipitocervical position.

PURPOSE: To describe occipitocervical inclination (OCI), a new parameter that could compensate for defects in existing radiographic parameters, and to define occipitocervical neutral position. METHODS: Neutral, flexion, and extension lateral cervical spine radiographs of 200 patients (100 male and 100 female patients) judged to be normal were analyzed. The mean age was 45.19 years (range 11-74; 42.84 for male and 47.53 for female patients). For OCI, the angle formed by the line connecting the posterior border of the C4 vertebral body and McGregor's line was measured. Occipitocervical angle (OCA) and occipitocervical distance (OCD) were measured and compared with OCI. RESULTS: OCI on standard, neutral lateral cervical radiographs was 102.51° ± 8.87°. There was no significant gender difference in neutral OCI 102.81° ± 7.93° for male and 102.21° ± 9.74° for female patients (P = 0.631). The mean neutral OCA was 38.69° ± 9.23°, and the mean neutral OCD was 22.98 ± 5.10 mm. Pearson's correlation coefficient for the value of the cervical lordosis angle and that of neutral OCI was r = 0.274 (P < 0.001). Intraclass correlation coefficient values for inter- and intraobserver reliability for OCI were significantly higher than those for OCA (P < 0.001) and tended to be higher than those for OCD (P = 0.087). CONCLUSIONS: OCI is a very useful parameter for the determination of neutral position during occipitocervical fusion for patients with altered C0-C2 anatomy.

Deltoid muscle volume affects clinical outcome of reverse total shoulder arthroplasty in patients with cuff tear arthropathy or irreparable cuff tears.

We aimed to estimate the interrelation between preoperative deltoid muscle status by measuring the 3-dimensional deltoid muscle volume and postoperative functional outcomes after reverse total shoulder arthroplasty(RTSA). Thirty-five patients who underwent RTSA participated in this study. All patients underwent preoperative magnetic resonance imaging(MRI) as well as pre- and postoperative radiography and various functional outcome evaluations at least 1 year. The primary outcome parameter was set as age- and sex-matched Constant scores. The 3-dimensional deltoid muscle model was generated using a medical image processing software and in-house code, and the deltoid muscle volume was calculated automatically. Various clinical and radiographic factors comprising the deltoid muscle volume adjusted for body mass index(BMI) were analyzed, and their interrelation with the outcome parameters was appraised using a multivariate analysis. As a result, all practical consequences considerably improved following surgery(all p<0.01). Overall, 20 and 15 indicated a higher and a lower practical consequence than the average, respectively, which was assessed by the matched Constant scores. The deltoid muscle volume adjusted for BMI(p = 0.009), absence of a subscapularis complete tear (p = 0.040), and greater change in acromion-deltoid tuberosity distance(p = 0.013) were associated with higher matched Constant scores. Multivariate analysis indicated that the deltoid muscle volume was the single independent prognostic factor for practical consequences(p = 0.011). In conclusion, the preoperative deltoid muscle volume significantly affected the functional outcome following RTSA in patients with cuff tear arthropathy or irreparable cuff tears. Therefore, more attention should be paid to patients with severe atrophied deltoid muscle who are at a high risk for poor practical consequences subsequent to RTSA.

Cervical subtotal en-bloc spondylectomy of C6 mesenchymal chondrosarcoma.

INTRODUCTION: We present a case of C6 mesenchymal chondrosarcoma and discuss safe posterior to anterior approach subtotal en-bloc spondylectomy. MATERIALS AND METHODS: A 29-year-old male consulted for our department with severe posterior neck pain doing exercise. CT scan demonstrated a primary osteolytic lesion on C6 left transverse foramen and MRI demonstrated the tumor involved C6 vertebra from layers B, C and F sectors 4-6 encasing left vertebral artery. Preoperatively neurointerventional radiology service occluded the left vertebral artery and tumor feeding artery using coil embolization. Posterior approach consist of C5-C7 laminectomy, left sided C6 and C7 nerve root sacrifice, posterior disc removal and release of C5-6-7 and posterior reconstruction. Then, position was changed to supine, and the anterior approach was followed as C5-6, C6-7 discectomy, left vertebral artery ligation and cut, longus coli resection and C6 subtotal spondylectomy with en-bloc resection of mass, mesh cage insertion and C5-C7 anterior plate fixation. During operation, frozen biopsy was performed on 8 areas (longus coli, lateral margin, anteroinferior margin, posterior margin, posterosuperior margin, C5 transverse foramen, posteroinferior margin, inferior margin) after wide resection. Tumor free margin was confirmed. RESULTS: After operation, he complained of tingling sensation of left thumb and forearm medial side, and elbow extensor motor grade was checked to 4/5 postoperatively. In the followed-up radiograph, the tumor was completely removed, and the instability of joint was not seen. As a result of observing follow-up CT at a year after the surgery, recurrence findings have not been shown up to now, and the progression of neurologic symptoms has not been shown either. CONCLUSION: Based on the Grand Round case and relevant literature, we discuss the case of mesenchymal chondrosarcoma occurring from the C6 cervical spine treated with cervical subtotal en-bloc spondylectomy. Successful en-bloc resection of the tumor was achieved using posterior to anterior approach.

Single-Bundle Anterior Cruciate Ligament Reconstruction with Semitendinosus Tendon Using the PINN-ACL CrossPin System: Minimum 4-Year Follow-up.

PURPOSE: This study evaluated mid-term results of anterior cruciate ligament (ACL) reconstruction using the PINN-ACL CrossPin system that allowed for short graft fixation. MATERIALS AND METHODS: Forty-three patients underwent single-bundle ACL reconstruction with a 4-strand semitendinosus tendon graft using the PINN-ACL CrossPin system. Femoral fixation was done using the PINN-ACL CrossPin system, and the tibial side was fixed with post-tie and a bioabsorbable interference screw. The mean follow-up period was 50 months. Evaluation was done using the Lachman test, pivot-shift test, International Knee Documentation Committee (IKDC) score and grade. Anterior displacement was assessed. RESULTS: There was improvement in the Lachman test and pivot-shift test at final follow-up, form grade II (n=40) or III (n=3) to grade I (n=3) or 0 (n=40) and from grade I (n=20) or II (n=10) to grade I (n=8) or 0 (n=22), respectively. The mean IKDC score was 88.7, and grade A and B were 93.0% at final follow-up. Side-to-side difference was improved from 6.7 mm to 2.1 mm at final follow-up. Complications occurred in 3 patients, a re-ruptured due to trauma at 2 years after surgery and a deep infection and a superficial infection. CONCLUSIONS: The mid-term follow-up results of ACL reconstruction with the PINN-ACL CrossPin system were satisfactory. The PINN-ACL CrossPin can be considered as a useful instrument for short graft fixation.

Association between a change in donor kidney function and long-term allograft outcomes in kidney transplant recipients.

Reserve capacity of donated kidney may be an important determinant of allograft survival in kidney transplantation (KT). Here, we investigate change in estimated glomerular filtration rate of donor kidney (ΔeGFR(Donor)) over 30 days after KT as a predictor of the allograft function. A total of 222 recipients were divided into two groups according to ΔeGFR(Donor) as follows: Group I (n = 110), ΔeGFR(Donor) ≥ -25%; Group II (n = 112), ΔeGFR(Donor) < -25%. Three years after KT, Group I had a higher eGFR(Recipient) than Group II (55 ± 21 vs. 47 ± 22 mL/min/1.73 m2, P < 0.05). However, no differences in eGFR(Recipient) were detected between the two groups after 10 years. Linear regression analysis showed that ΔeGFR(Donor) was significantly associated with the eGFR(Recipient) at 3 years post-transplantation, but not at 10 years post-transplantation. In Kaplan-Meier analysis, Group I had a greater dialysis-free survival rate than Group II at the 10-year follow-up (84% vs. 76%, P < 0.05). However, no difference in overall survival rate between groups was detected. In the multivariate-adjusted Cox proportional-hazard model, ΔeGFR(Donor) was independently associated with future allograft loss (hazard ratio 0.973; 95% confidence interval 0.949-0.999). These results suggest that larger recovery of donor kidney function after KT donation is associated with better short/intermediate-term allograft outcomes. Follow-up assessment of donor kidney function may be useful to monitor KT recipients at risk for allograft loss.

Comparison and correlation of pelvic parameters between low-grade and high-grade spondylolisthesis.

STUDY DESIGN: This study was retrospectively conducted on 51 patients with L5-S1 spondylolisthesis. OBJECTIVE: This study was conducted to compare a total of 11 pelvic parameters, such as the level of displacement by Meyerding method, lumbar lordosis, sacral inclination, lumbosacral angle, slip angle, S2 inclination, pelvic incidence (PI), L5 inclination, L5 slope, pelvic tilt (PT), and sacral slope (SS) between low-grade and high-grade spondylolisthesis, and to investigate a correlation of the level of displacement by Meyerding method with other pelvic parameters. METHODS: Pelvic parameters were measured using preoperational erect lateral spinal simple radiographs. The patients were divided into 39 patients with low-grade spondylolisthesis and 12 patients with high-grade spondylolisthesis before analysis. In all patients of both groups, 11 radiographic measurements including the level of displacement by Meyerding method, lumbar lordosis, sacral inclination, lumbosacral angle, slip angle, S2 inclination, PI, L5 inclination, L5 slope, PT, and SS were performed. T test and Pearson correlation analysis were conducted to compare and analyze each measurement. RESULTS: As for the comparison between the 2 groups, a statistically great significance in the level of displacement by Meyerding method, lumbosacral angle, slip angle, L5 incidence, PI, and L5 slope (P≤0.001) was shown. Meanwhile, a statistical significance in the sacral inclination and PT (P<0.05) was also shown. However, no statistical significance in the S2 incidence and SS was shown. A correlation of the level of displacement by Meyerding method with each parameter was analyzed in the both the groups. A high correlation was observed in the lumbar lordosis, lumbosacral angle, slip angle, L5 incidence, and L5 slope (Pearson correlation coefficient, P=0.01), as well as the sacral inclination, PI, and PT (Pearson correlation coefficient, P=0.05). Meanwhile, no correlation was shown in the S2 incidence and SS. CONCLUSIONS: A significant difference in the lumbosacral angle, slip angle, L5 incidence, PI, L5 slope, sacral inclination, and PT was shown between the patients with high-grade spondylolisthesis and patients with low-grade spondylolisthesis. Among the aforementioned measurements, the PI showed a significant difference between the 2 groups and also had a significant correlation with the dislocation level in all the patients.

Association of heart rate and left ventricular structure in a rural population in Korea.

Abstract We investigated the association of heart rate (HR) and estimated glomerular filtration rate (eGFR) with left ventricular (LV) structure in a multi-rural cohort project in Korea. A total of 3215 subjects were analyzed for factors related to Echo-LV mass index (LVMI). eGFR was positively associated with both types of LVMI whereas HR was negatively associated with both. Odd ratios (ORs) (highest versus lowest quartiles) for LVMI by height(2.7) were significant for HR (OR: 0.441, p = 0.0035 in males; OR: 0.638, p = 0.0226 in females), and for eGFR (OR:1.643, p = 0.0145) in females. In conclusion, in addition to age, systolic blood pressure and body mass index, eGFR is positively associated with echocardiographic LVMI and HR is negatively associated with echocardiographic LVMI.

Bilateral renal cortical necrosis following binge drinking.

Renal cortical necrosis (RCN) is a rare cause of acute kidney injury secondary to ischemic necrosis of the renal cortex. Acute tubular necrosis after binge drinking is usually attributed to volume depletion, idiosyncratic reaction to alcohol, rhabdomyolysis or a combination with non-steroidal anti-inflammatory drugs. Binge drinking itself as a cause of RCN has not yet been reported. We report a case of a 25-year-old Asian male who developed bilateral RCN following binge drinking.

Field Emission of ITO-Coated Vertically Aligned Nanowire Array.

An indium tin oxide (ITO)-coated vertically aligned nanowire array is fabricated, and the field emission characteristics of the nanowire array are investigated. An array of vertically aligned nanowires is considered an ideal structure for a field emitter because of its parallel orientation to the applied electric field. In this letter, a vertically aligned nanowire array is fabricated by modified conventional UV lithography and coated with 0.1-µm-thick ITO. The turn-on electric field intensity is about 2.0 V/µm, and the field enhancement factor, ß, is approximately 3,078 when the gap for field emission is 0.6 µm, as measured with a nanomanipulator in a scanning electron microscope.