26 research outputs found
Machine Learning Outperforms Regression Analysis to Predict Next-Season Major League Baseball Player Injuries: Epidemiology and Validation of 13,982 Player-Years From Performance and Injury Profile Trends, 2000-2017
Background: Machine learning (ML) allows for the development of a predictive algorithm capable of imbibing historical data on a Major League Baseball (MLB) player to accurately project the player\u27s future availability.
Purpose: To determine the validity of an ML model in predicting the next-season injury risk and anatomic injury location for both position players and pitchers in the MLB.
Study Design: Descriptive epidemiology study.
Methods: Using 4 online baseball databases, we compiled MLB player data, including age, performance metrics, and injury history. A total of 84 ML algorithms were developed. The output of each algorithm reported whether the player would sustain an injury the following season as well as the injury\u27s anatomic site. The area under the receiver operating characteristic curve (AUC) primarily determined validation.
Results: Player data were generated from 1931 position players and 1245 pitchers, with a mean follow-up of 4.40 years (13,982 player-years) between the years of 2000 and 2017. Injured players spent a total of 108,656 days on the disabled list, with a mean of 34.21 total days per player. The mean AUC for predicting next-season injuries was 0.76 among position players and 0.65 among pitchers using the top 3 ensemble classification. Back injuries had the highest AUC among both position players and pitchers, at 0.73. Advanced ML models outperformed logistic regression in 13 of 14 cases.
Conclusion: Advanced ML models generally outperformed logistic regression and demonstrated fair capability in predicting publicly reportable next-season injuries, including the anatomic region for position players, although not for pitchers
Skin Lesions on Common Bottlenose Dolphins (Tursiops truncatus) from Three Sites in the Northwest Atlantic, USA
Skin disease occurs frequently in many cetacean species across the globe; methods to categorize lesions have relied on photo-identification (photo-id), stranding, and by-catch data. The current study used photo-id data from four sampling months during 2009 to estimate skin lesion prevalence and type occurring on bottlenose dolphins (Tursiops truncatus) from three sites along the southeast United States coast [Sarasota Bay, FL (SSB); near Brunswick and Sapelo Island, GA (BSG); and near Charleston, SC (CHS)]. The prevalence of lesions was highest among BSG dolphins (P = 0.587) and lowest in SSB (P = 0.380), and the overall prevalence was significantly different among all sites (p<0.0167). Logistic regression modeling revealed a significant reduction in the odds of lesion occurrence for increasing water temperatures (OR = 0.92; 95%CI:0.906–0.938) and a significantly increased odds of lesion occurrence for BSG dolphins (OR = 1.39; 95%CI:1.203–1.614). Approximately one-third of the lesioned dolphins from each site presented with multiple types, and population differences in lesion type occurrence were observed (p<0.05). Lesions on stranded dolphins were sampled to determine the etiology of different lesion types, which included three visually distinct samples positive for herpesvirus. Although generally considered non-fatal, skin disease may be indicative of animal health or exposure to anthropogenic or environmental threats, and photo-id data provide an efficient and cost-effective approach to document the occurrence of skin lesions in free-ranging populations
Spectrograph design for the Asgard/BIFROST spectro-interferometric instrument for the VLTI
This is the author accepted manuscript.The BIFROST instrument will be the first VLTI instrument optimised for high spectral resolution up to R=25,000 and operate between 1.05 and 1.7 µm. A key component of the instrument will be the spectrograph, where we require a high throughput over a broad bandwidth. In this contribution, we discuss the four planned spectral modes (R=50, R=1000, R=5000, and R=25,000), the key spectral windows that we need to cover, and the technology choices that we have considered. We present our plan to use Volume Phase Holographic Gratings (VPHGs) to achieve a high efficiency > 85%. We present our preliminary optical design and our strategies for wavelength calibration.European Research Council (ERC)Science and Technology Facilities Council (STFC
The Determination of Interobserver and Intraobserver Reliability of a Magnetic Resonance Imaging Based Classification System for Ulnar Collateral Ligament Injury
Background: Despite improvements in the biomechanics and surgical options for UCL tears, there remains a need for a reliable classification of UCL tears that has the potential to guide clinical decision-making. Purpose: The purpose of this cross-sectional study was to assess the intraobserver and interobserver reliability of the newly proposed MRI-based classification to UCL tears. Secondary objectives included assessing the impact of additional views, discrimination between distal and non-distal tears, and correlation of imaging reads with intraoperative findings of the UCL. Methods: Nine fellowship-trained specialists from seven institutions independently completed four series surveys consisting of 60 total elbow MRIs with UCL tears using a newly proposed six-stage classification system. The first and third surveys contained a total of 60 coronal MRI images, while the second and fourth contained the same MRI images with both coronal and axial views presented in a random order to assess intraobserver variability using the weighted kappa value and impact of additional imaging views. Weighted kappa values were also calculated for each of the four surveys to acquire interobserver reliability. Reliability analysis was repeated using a two-group classification analysis for distal and non-distal disease. Observer readings were compared to intraoperative UCL findings. Results: For the newly proposed six-stage MRI-based classification, intraobserver and interobserver reliability demonstrated near perfect and substantial agreement, respectively. These values only increased when sub-stratified into the two-group distal and non-distal disease classification (p\u3c0.05). The additional axial view did not statistically improve the agreement between and among readers. Observer readings were accurate for tear grade (partial and complete), proximal location, and distal location, but not midsubstance tears, when compared to intraoperative findings from 30 elbows. Conclusion: Our newly proposed six-stage MRI-based classification utilizing grade and location of the injury was found to have substantial to near perfect agreement between and within fellowship-trained observers. The results of this study provide a foundation for future validation studies, in which the classification system may be associated with clinical decision-making and patient outcomes. [Figure presented] Top left: 1A, proximal partial Top right: 1B, proximal complete Middle left: 2A, midsubstance partial Middle right: 2B, midsubstance complete Bottom left: 3A, distal partial Top left: 3B, distal complete [Figure presented
The Determination of Interobserver and Intraobserver Reliability of a Magnetic Resonance Imaging Based Classification System for Ulnar Collateral Ligament Injury
Background: Despite improvements in the biomechanics and surgical options for UCL tears, there remains a need for a reliable classification of UCL tears that has the potential to guide clinical decision-making. Purpose: The purpose of this cross-sectional study was to assess the intraobserver and interobserver reliability of the newly proposed MRI-based classification to UCL tears. Secondary objectives included assessing the impact of additional views, discrimination between distal and non-distal tears, and correlation of imaging reads with intraoperative findings of the UCL. Methods: Nine fellowship-trained specialists from seven institutions independently completed four series surveys consisting of 60 total elbow MRIs with UCL tears using a newly proposed six-stage classification system. The first and third surveys contained a total of 60 coronal MRI images, while the second and fourth contained the same MRI images with both coronal and axial views presented in a random order to assess intraobserver variability using the weighted kappa value and impact of additional imaging views. Weighted kappa values were also calculated for each of the four surveys to acquire interobserver reliability. Reliability analysis was repeated using a two-group classification analysis for distal and non-distal disease. Observer readings were compared to intraoperative UCL findings. Results: For the newly proposed six-stage MRI-based classification, intraobserver and interobserver reliability demonstrated near perfect and substantial agreement, respectively. These values only increased when sub-stratified into the two-group distal and non-distal disease classification (p\u3c0.05). The additional axial view did not statistically improve the agreement between and among readers. Observer readings were accurate for tear grade (partial and complete), proximal location, and distal location, but not midsubstance tears, when compared to intraoperative findings from 30 elbows. Conclusion: Our newly proposed six-stage MRI-based classification utilizing grade and location of the injury was found to have substantial to near perfect agreement between and within fellowship-trained observers. The results of this study provide a foundation for future validation studies, in which the classification system may be associated with clinical decision-making and patient outcomes
Interobserver and Intraobserver Reliability of an MRI-Based Classification System for Injuries to the Ulnar Collateral Ligament.
BACKGROUND: Despite improvements in understanding biomechanics and surgical options for ulnar collateral ligament (UCL) tears, there remains a need for a reliable classification of UCL tears that has the potential to guide clinical decision making.
PURPOSE: To assess the intra- and interobserver reliability of the newly proposed magnetic resonance imaging (MRI)-based classification for UCL tears. Secondary objectives included assessing the effect of additional views, discrimination between distal and nondistal tears, and correlation of imaging reads with intraoperative findings of the UCL.
STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2.
METHODS: Nine fellowship-trained specialists from 7 institutions independently completed 4 surveys consisting of 60 elbow MRI scans with UCL tears using a newly proposed 6-stage classification system. The first and third surveys contained 60 coronal images, while the second and fourth contained the same images with coronal and axial views presented in a random order to assess intraobserver variability via the weighted kappa value and the effect of additional imaging views. Weighted kappa values were also calculated for each of the 4 surveys to acquire interobserver reliability. Reliability analysis was repeated through a 2-group classification analysis for distal and nondistal tears. Observer readings were compared with intraoperative UCL findings.
RESULTS: For the newly proposed 6-stage MRI-based classification, intra- and interobserver reliability demonstrated near perfect and substantial agreement, respectively. These values increased only when substratified into the 2-group distal and nondistal tear classification ( P \u3c .05). The additional axial view did not statistically improve the agreement within and among readers. When compared with intraoperative findings from 30 elbows, observer readings were accurate for tear grade (partial and complete), proximal location, and distal location but not midsubstance tears.
CONCLUSION: The newly proposed 6-stage MRI-based classification utilizing grade and location of the injury had substantial to near perfect agreement among and within fellowship-trained observers
Evaluation of Endothelial and Vascular-Derived Progenitor Cell Populations in the Proximal and Distal UCL of the Elbow: A Comparative Study
Background: Vascular-derived progenitor and endothelial cell populations (CD31, CD34, CD146) are capable of multipotent differentiation at the site of injured ligamentous tissue to aid in the intrinsic healing response. Proximal ulnar collateral ligament (UCL) tears have been reported to have better healing capability when compared with distal UCL tears. Purpose: To compare the vascular composition of the proximal and distal insertions of the anterior bundle of the UCL of the elbow via known markers of endothelial and vascular-derived progenitor cells (CD31, CD34, CD146). Study Design: Descriptive laboratory study. Methods: UCLs were harvested from 10 nonpaired fresh-frozen human cadaveric elbows and transected into proximal and distal portions. Endothelial and vascular-derived progenitor cell densities were assessed with 4 staining groups: CD31 (immunohistochemistry) and CD31/α-smooth muscle actin (α-SMA), CD34/α-SMA, and CD146/α-SMA (immunofluorescence). CD31 immunohistochemistry identified endothelial progenitor cells in the UCL. Later staining of the same slides with α-SMA demonstrated the relationship of progenitor cells to the surrounding vasculature. Fluorescent staining was quantified by calculating the proportion of positively stained nuclei versus the total number of nuclei in the proximal and distal UCL. Results: CD31+ cells were present in the proximal and distal sections of all 10 UCLs. Fluorescent staining revealed no significant differences in the ratio of CD31 to total nuclei between the distal (median, 36% [range, 23%-53%]) and proximal UCL (39% [22%-56%]) (P = .432, Wilcoxon signed-rank test). Similarly, no differences were seen between CD34 distal (39% [24%-64%]) and proximal regions (46% [28%-63%]) (P = .846, Wilcoxon signed-rank test) or CD146 distal (40% [12%-65%]) and proximal regions (40% [22%-51%]) (P ≥ .999, Wilcoxon signed-rank test). Conclusion: Analysis of UCL tissues demonstrated equal distributions of vascular endothelial and vascular-derived progenitor cell markers throughout the proximal and distal UCL. Unlike that of the medial collateral ligament of the knee, the microvascular composition of the proximal and distal UCL insertions was not different, suggesting a well-vascularized ligament throughout its course
Magnetic Glycol Chitin-Based Hydrogel Nanocomposite for Combined Thermal and d‑Amino-Acid-Assisted Biofilm Disruption
Bacterial biofilms
are highly antibiotic resistant microbial cell associations that lead
to chronic infections. Unlike free-floating planktonic bacterial cells,
the biofilms are encapsulated in a hardly penetrable extracellular
polymeric matrix and, thus, demand innovative approaches for treatment.
Recent advancements on the development of gel-nanocomposite systems
with tailored therapeutic properties provide promising routes to develop
novel antimicrobial agents that can be designed to disrupt and completely
eradicate preformed biofilms. In our study, we developed a unique
thermoresponsive magnetic glycol chitin-based nanocomposite containing d-amino acids and iron oxide nanoparticles, which can be delivered
and undergoes transformation from a solution to a gel state at physiological
temperature for sustained release of d-amino acids and magnetic
field actuated thermal treatment of targeted infection sites. The d-amino acids in the hydrogel nanocomposite have been previously
reported to inhibit biofilm formation and also disrupt existing biofilms.
In addition, loading the hydrogel nanocomposite with magnetic nanoparticles
allows for combination thermal treatment following magnetic field
(magnetic hyperthermia) stimulation. Using this novel two-step approach
to utilize an externally actuated gel-nanocomposite system for thermal
treatment, following initial disruption with d-amino acids,
we were able to demonstrate in vitro the total eradication of <i>Staphylococcus aureus</i> biofilms, which were resistant to
conventional antibiotics and were not completely eradicated by separate d-amino acid or magnetic hyperthermia treatments