Bulletin of Computer Science and Electrical Engineering (BCSEE)
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Rapid fiber alignment quantification in direct write printing of short fiber reinforced composites
No full textShort fiber reinforced polymer composites fabricated by direct ink writing (DW) have design flexibility, low cost, and tailored property advantages over traditional composite materials. Controlling fiber alignment in these composite systems can be used to design unique materials with direction-dependent properties, especially when coupled to topology optimization for light weighting and high strength. . This study focuses on controlling fiber alignment in short carbon fiber composites with two printing parameters common in DW systems: nozzle diameter and velocity ratio. To do so, a novel rapid fiber alignment analysis (RFAA) was developed to quickly collect large amounts of fiber alignment data. Compared to the conventional fiber alignment quantification technique, X-Ray CT, RFAA is a rapid, accurate, and low-cost alternative. It was determined that fiber alignment can be enhanced by printing with smaller nozzle diameters and higher velocity ratios. Longitudinal bending stiffness and bending strength improved as the fiber alignment increased. Composites printed with low fiber alignment exhibited isotropic mechanical properties. However, aligning the fibers in the composite resulted in direction-dependent properties with significantly enhanced modulus and strength in the alignment direction
Analyzing pediatric bicycle injuries using geo-demographic data
No full textBicycle accidents are potentially preventable, and helmets can mitigate the severity of injuries. The purpose of the study it to investigate geo-demographic areas to establish prevention policies and targeted programs.
From October 2013 to March 2020 all bicycle injuries at a Level 1 trauma center were collected for ages ≤18 years. Demographics, injuries, and outcomes were analyzed. Incidents were aggregated to zip codes and the Local Indicators of Spatial Association (LISA) statistic was used to test for spatial clustering of injury rates per 10,000 children.
Over the 8-year time period, 77 cases were identified with an average age of 13±4 years, 83% male and 48% non-Hispanic white. The majority of patients (98%) were not wearing a helmet. Loss of consciousness was reported in 44% and 21% sustained a traumatic brain injury. Twenty-eight percent required ICU care and 36% required operative interventions. There was only 1 mortality in the cohort (<1%).Injuries were more common in lower household income zip codes (Figure 1). Six zip codes encompassing several interstate exits and the connected heavy-traffic roadways comprise a statistically significant cluster of pediatric bicycle accidents (Figure 1).
Low-income neighborhoods and those near major roadways held the highest risk for pediatric bicycle accidents. Use of helmets was extremely low in the patient population, with high rates of traumatic brain injury. With this information, targeted programs to address high-risk intersections, helmet access, and safety education can be implemented locally
Coats plus in prematurity
No full textCoats plus syndrome or cerebroretinal microangiopathy with calcifications and cysts (CMCC) is an exceedingly rare autosomal recessive disorder that predominantly affects the microvasculature in the retina, brain, bones, and gastrointestinal system. Unlike Coats disease, CMCC is bilateral and affects multiple organ systems.
Case report
We report the case of two brothers with Coats Plus syndrome who presented with variable phenotypic expression. One sibling (Patient 1) was thought to have atypical retinopathy of prematurity and was only diagnosed with Coats plus after his older brother (Patient 2) presented with a seizure and a left upper extremity tremor at 4 years of age. The CTC1 mutation was confirmed in both patients. Aggressive treatment with laser photocoagulation and intravitreal bevacizumab dramatically improved the retinal vascular and exudative changes.
Coats Plus syndrome can have a variable phenotypic presentation, including retinal vascular findings. This rare genetic disease should be in the differential diagnosis in patients who present with atypical retinal pathology, including Retinopathy of Prematurity, Familial Exudative Vitreoretinopathy, or Coats disease associated with non-specific multiorgan abnormalities
Automated segmentation of the ciliary muscle in OCT images using fully convolutional networks
No full textDiagnostic Accuracy of Pyrazinamide Susceptibility Testing in Mycobacterium tuberculosis : A Systematic Review with Meta-Analysis
No full textPyrazinamide (PZA) susceptibility testing plays a critical role in determining the appropriate treatment regimens for multidrug-resistant tuberculosis. We conducted a systematic review and meta-analysis to evaluate the diagnostic accuracy of sequencing PZA susceptibility tests against culture-based susceptibility testing methods as the reference standard.
We searched the MEDLINE/PubMed, Embase, and Web of Science databases for the relevant records. The QUADAS-2 tool was used to assess the quality of the studies. Diagnostic accuracy measures (
, sensitivity and specificity) were pooled with a random-effects model. All statistical analyses were performed with Meta-DiSc (version 1.4, Cochrane Colloquium, Barcelona, Spain), STATA (version 14, Stata Corporation, College Station, TX), and RevMan (version 5.3, The Nordic Cochrane Centre, the Cochrane Collaboration, Copenhagen, Denmark) software.
A total of 72 articles, published between 2000 and 2019, comprising data for 8,701 isolates of
were included in the final analysis. The pooled sensitivity and specificity of the PZA sequencing test against all reference tests (the combination of BACTEC mycobacteria growth indicator tube 960 (MGIT 960), BACTEC 460, and proportion method) were 87% (95% CI: 85-88) and 94.7% (95% CI: 94-95). The positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and the area under the curve estimates were found to be 12.0 (95% CI: 9.0-16.0), 0.17 (95% CI: 0.13-0.21), 106 (95% CI: 71-158), and 96%, respectively. Deek's test result indicated a low likelihood for publication bias (
= 0.01).
Our analysis indicated that PZA sequencing may be used in combination with conventional tests due to the advantage of the time to result and in scenarios where culture tests are not feasible. Further work to improve molecular tests would benefit from the availability of standardized reference standards and improvements to the methodology
COST ANALYSIS OF SCLERAL BUCKLE, PARS PLANA VITRECTOMY, AND PARS PLANA VITRECTOMY WITH SCLERAL BUCKLE FOR RETINAL DETACHMENT REPAIR
No full textTo compare the cost and utility of scleral buckle (SB), pars plana vitrectomy (PPV), and PPV with SB (PPV/SB) for moderately complex rhegmatogenous retinal detachment repair.
Cost-utility analysis using data from the Primary Retinal Detachment Outcomes Study. The model estimated costs, lifetime utility, and lifetime cost per quality-adjusted life year for treatment of moderately complex rhegmatogenous retinal detachment with SB, PPV, or PPV/SB. Data from the Centers for Medicare and Medicaid Services were used to calculate costs in hospital and ambulatory surgery center settings.
Total costs (2020 US dollars) for repair of a moderately complex rhegmatogenous retinal detachment in hospital (ambulatory surgery center) settings were 3,774) for the SB group, 5,082) for the PPV group, and 4,713) for the PPV/SB group. The estimated lifetime quality-adjusted life years gained were 5.4, 4.7, and 4.7 in the SB, PPV, and PPV/SB groups, respectively. The cost per quality-adjusted life year for hospital and ambulatory surgery center settings was 699) for the SB group, 1,081) for the PPV group, and 1,003) for the PPV/SB group.
Scleral buckle, PPV, and PPV/SB yielded very favorable cost-utility results for the repair of moderately complex rhegmatogenous retinal detachment, with slightly better results for SB, compared with current willingness to pay standards
Boosting for Multivariate Longitudinal Responses
No full textBoosting, a machine learning approach, has gained popularity over the years in its application to various types of data, including longitudinal data. However, its application to data involving multivariate responses is limited. In this article, we present a new approach where we apply gradient boosting, a generic form of boosting, to model multivariate longitudinal responses. Our approach can handle time-varying covariates as well as high dimensionality of covariates and responses when some of the covariates and responses are pure noise. A key feature of our approach is that it is designed to select covariates that affect responses differently at different time intervals; thereby, an overall effect of any covariate can be dissected and represented as a function of time. A novel feature of our approach is that, in addition to covariate selection, we also perform response selection for different time intervals. This helps to identify and order responses based on their importance for a given time interval. Simulation results show that the prediction performance of our approach does not deteriorate in high dimensionality and can approximate the true model. Application of our approach to a clinical laboratory data evaluates the behavior of bilirubin and creatinine for the heart failure patients before and after the heart transplant, and identifies important risk factors that affect their behavior. Our approach can be implemented using the R package BoostML
Relationships between species richness and ecosystem services in Amazonian forests strongly influenced by biogeographical strata and forest types
No full textDespite increasing attention for relationships between species richness and ecosystem services, for tropical forests such relationships are still under discussion. Contradicting relationships have been reported concerning carbon stock, while little is known about relationships concerning timber stock and the abundance of non-timber forest product producing plant species (NTFP abundance). Using 151 1-ha plots, we related tree and arborescent palm species richness to carbon stock, timber stock and NTFP abundance across the Guiana Shield, and using 283 1-ha plots, to carbon stock across all of Amazonia. We analysed how environmental heterogeneity influenced these relationships, assessing differences across and within multiple forest types, biogeographic regions and subregions. Species richness showed significant relationships with all three ecosystem services, but relationships differed between forest types and among biogeographical strata. We found that species richness was positively associated to carbon stock in all biogeographical strata. This association became obscured by variation across biogeographical regions at the scale of Amazonia, resembling a Simpson's paradox. By contrast, species richness was weakly or not significantly related to timber stock and NTFP abundance, suggesting that species richness is not a good predictor for these ecosystem services. Our findings illustrate the importance of environmental stratification in analysing biodiversity-ecosystem services relationships