19 research outputs found
Investing in Online Peer to Peer Loans: A Platform for Alpha
Peer to peer (P2P) lending is an emerging asset class that potentially offers investors relatively high risk adjusted returns and a good way to diversify portfolios. However, little research has empirically explored the returns of P2P loans. This study explores the investment returns of P2P loans and the impact of P2P loans on investment portfolios. We draw data from the leading P2P lending platform, Lending Club, and compare the 2007-2014 investment returns from Lending Club to other assets and look at how P2P loans affect the efficiency of portfolios. The results suggest that P2P loans offer relatively high risk adjusted returns that can improve the efficiency of investment portfolios and can help investors achieve alph
Automated interpretation of systolic and diastolic function on the echocardiogram:a multicohort study
Background: Echocardiography is the diagnostic modality for assessing cardiac systolic and diastolic function to diagnose and manage heart failure. However, manual interpretation of echocardiograms can be time consuming and subject to human error. Therefore, we developed a fully automated deep learning workflow to classify, segment, and annotate two-dimensional (2D) videos and Doppler modalities in echocardiograms. Methods: We developed the workflow using a training dataset of 1145 echocardiograms and an internal test set of 406 echocardiograms from the prospective heart failure research platform (Asian Network for Translational Research and Cardiovascular Trials; ATTRaCT) in Asia, with previous manual tracings by expert sonographers. We validated the workflow against manual measurements in a curated dataset from Canada (Alberta Heart Failure Etiology and Analysis Research Team; HEART; n=1029 echocardiograms), a real-world dataset from Taiwan (n=31 241), the US-based EchoNet-Dynamic dataset (n=10 030), and in an independent prospective assessment of the Asian (ATTRaCT) and Canadian (Alberta HEART) datasets (n=142) with repeated independent measurements by two expert sonographers. Findings: In the ATTRaCT test set, the automated workflow classified 2D videos and Doppler modalities with accuracies (number of correct predictions divided by the total number of predictions) ranging from 0·91 to 0·99. Segmentations of the left ventricle and left atrium were accurate, with a mean Dice similarity coefficient greater than 93% for all. In the external datasets (n=1029 to 10 030 echocardiograms used as input), automated measurements showed good agreement with locally measured values, with a mean absolute error range of 9â25 mL for left ventricular volumes, 6â10% for left ventricular ejection fraction (LVEF), and 1·8â2·2 for the ratio of the mitral inflow E wave to the tissue Doppler e' wave (E/e' ratio); and reliably classified systolic dysfunction (LVEF <40%, area under the receiver operating characteristic curve [AUC] range 0·90â0·92) and diastolic dysfunction (E/e' ratio â„13, AUC range 0·91â0·91), with narrow 95% CIs for AUC values. Independent prospective evaluation confirmed less variance of automated compared with human expert measurements, with all individual equivalence coefficients being less than 0 for all measurements. Interpretation: Deep learning algorithms can automatically annotate 2D videos and Doppler modalities with similar accuracy to manual measurements by expert sonographers. Use of an automated workflow might accelerate access, improve quality, and reduce costs in diagnosing and managing heart failure globally. Funding: A*STAR Biomedical Research Council and A*STAR Exploit Technologies
The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data
This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library (MaStar) accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) survey which publicly releases infra-red spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the sub-survey Time Domain Spectroscopic Survey (TDSS) data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey (SPIDERS) sub-survey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated Value Added Catalogs (VACs). This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper (MWM), Local Volume Mapper (LVM) and Black Hole Mapper (BHM) surveys
A Shock Tube Study of the Ignition of n-Heptane, n-Decane, n-Dodecane, and n-Tetradecane at Elevated Pressures
Two Multidrug-Resistant Clinical Isolates of Bacteroides fragilis Carry a Novel Metronidazole Resistance nim
Lip Bumper Therapy Does Not Influence the Sagittal Mandibular Incisor Position in a Retrospective CBCT Study
Lip bumper (LB) therapy is used as a treatment approach for mild to moderate crowding without extraction of teeth. Previous studies demonstrated that LB increases arch length through molar uprighting and lateral expansion. However, the effects of LB on mandibular incisors are inconclusive. The controversial results from different studies may be due to limitations including absence of a control group and/or use of 2D radiography. To address this issue, the current retrospective longitudinal CBCT study compared a rapid maxillary expansion (RME) group with no lower treatment [16 patients (9 females, 7 males); median age 8.86 years at T1 and 11.82 years at T2] and an RME + LB group [18 patients (13 females, 5 males); median age 9.46 years at T1 and 12.10 years at T2]. The CBCTs taken before and after phase 1 treatment were 3D superimposed based on the mandibular structure and were measured to determine the angular and linear changes of the mandibular incisors over the course of LB treatment. For comparisons between different timepoints within a group, a Wilcoxon matched-pairs signed rank test was used. For intergroup comparisons, a Mann–Whitney U test was used. Both groups showed eruption and protrusion of the mandibular incisors during the observation period, while there was no significant change in proclination of the lower incisors. When comparing the discrepancy of change between groups, there was no statistically significant difference detected. In summary, by utilizing a longitudinal 3D database, the current study demonstrated that the effect of LB on the position of the mandibular incisors is limited
Salvage prostate cryoablation for recurrent localized prostate cancer after radiotherapy
AbstractSalvage prostate cryoablation (SCA) for recurrent localized prostate cancer after radiotherapy has been studied in Western countries for more than a decade. We present our experience of SCA in a Taiwanese medical center. We performed four cases of SCA for recurrent localized prostate cancer after radiotherapy. The data recorded included age, cancer stage, prostate-specific antigen (PSA) level, Gleason score, prostate volume and patient outcome. The median follow-up period was 17 months. All cases were biopsy-proven to have residual cancer before cryoablation. After SCA, 25% of the patients reached undetectable PSA levels, 50% showed response but did not reach undetectable levels, and 25% showed no decrease in PSA. The median recurrence-free duration after SCA was 18 months in the patients who experienced a decrease in PSA. ADT was initiated after SCA for the patient who did not show any response, and bone metastasis was later diagnosed in that patient. Most patients experienced obstructive voiding problems after SCA, which improved over time. SCA is a safe salvage option for prostate cancer patients with local recurrence after RT. The preliminary results are encouraging. More extensive imagery to exclude extra-glandular disease is warranted before SCA. A longer follow-up period and larger sample size are necessary to delineate the benefits more conclusively
A Shock Tube Study of the Ignition of n-Heptane, n-Decane, n-Dodecane, and n-Tetradecane at Elevated Pressures
The ignition of n-heptane, n-decane, n-dodecane, and n-tetradecane has been investigated in a heated shock tube. n-Alkane/air mixtures at Ί = 0.25, 0.5, and 1.0 were studied in reflected shock experiments at 9â58 atm and 786â1396 K. Ignition times were measured using a combination of endwall electronically excited OH emission and sidewall pressure measurements. The measured ignition times are compared to previous data, where available, with good agreement and to several kinetic modeling predictions. The current data and the combination of the current data with previous shock tube and rapid compression machine measurements show that any differences in reactivity for C<sub>7</sub> and larger n-alkanes is slight, within the experimental uncertainties, for n-alkane/air mixtures with common carbon content at a large range of temperatures (650â1400 K) and elevated pressures. To our knowledge, the n-tetradecane measurements presented here are the first ignition measurements to be reported for this compound. The complete data set greatly extends the kinetic modeling targets available for large n-alkanes at elevated-pressure conditions relevant to practical combustion devices
Heterogeneity in stone culture protocols and endourologist practice patterns: a multi-institutional survey
Kidney stone cultures can be beneficial in identifying bacteria not detected in urine, yet how stone cultures are performed among endourologists, under what conditions, and by what laboratory methods remain largely unknown. Stone cultures are not addressed by current clinical guidelines. A comprehensive REDCap electronic survey sought responses from directed (nâ=â20) and listserv elicited (nâ=â108) endourologists specializing in kidney stone disease. Questions included which clinical scenarios prompt a stone culture order, how results influence post-operative antibiotics, and what microbiology lab protocols exist at each institution with respect to processing and resulting stone cultures. Logistic regression statistical analysis determined what factors were associated with performing stone cultures. Of 128 unique responses, 11% identified as female and the mean years of practicing was 16 (range 1-46). A specific \u27stone culture\u27 order was available to only 50% (64/128) of those surveyed, while 32% (41/128) reported culturing stone by placing a urine culture order. The duration of antibiotics given for a positive stone culture varied, with 4-7 days (46%) and 8-14 days (21%) the most reported. More years in practice was associated with fewer stone cultures ordered, while higher annual volume of percutaneous nephrolithotomy was associated with ordering more stone cultures (pâ\u3câ0.01). Endourologists have differing practice patterns with respect to ordering stone cultures and utilizing the results to guide post-operative antibiotics. With inconsistent microbiology lab stone culture protocols across multiple institutions, more uniform processing is needed for future studies to assess the clinical benefit of stone cultures and direct future guidelines