375 research outputs found
Placental Flattening via Volumetric Parameterization
We present a volumetric mesh-based algorithm for flattening the placenta to a
canonical template to enable effective visualization of local anatomy and
function. Monitoring placental function in vivo promises to support pregnancy
assessment and to improve care outcomes. We aim to alleviate visualization and
interpretation challenges presented by the shape of the placenta when it is
attached to the curved uterine wall. To do so, we flatten the volumetric mesh
that captures placental shape to resemble the well-studied ex vivo shape. We
formulate our method as a map from the in vivo shape to a flattened template
that minimizes the symmetric Dirichlet energy to control distortion throughout
the volume. Local injectivity is enforced via constrained line search during
gradient descent. We evaluate the proposed method on 28 placenta shapes
extracted from MRI images in a clinical study of placental function. We achieve
sub-voxel accuracy in mapping the boundary of the placenta to the template
while successfully controlling distortion throughout the volume. We illustrate
how the resulting mapping of the placenta enhances visualization of placental
anatomy and function. Our code is freely available at
https://github.com/mabulnaga/placenta-flattening .Comment: MICCAI 201
Indiana University’s Affordable E-text Model and Strategies to Increase Impact Beyond Savings – The Evolution of Affordable Content Efforts in the Higher Education Environment: Programs, Case Studies, and Examples
Hyperinflation in overall college costs and in textbook prices in the last decade is no secret, as demonstrated by extensive coverage in several major news reports. High textbook prices are deterring students from buying required textbooks or taking courses that have high-priced textbooks. The cost of textbooks, in other words, gets in the way of learning, and derails students from degrees they want to pursue in college.
Many universities and even state systems (Acker, 2011) are trying to lower the cost of textbooks for students. Indiana University (IU) started a pilot e-text program in 2009 to make publisher/commercial content more affordable. The program is based on an inclusive access model, addressed in more detail in the previous two chapters of this book. After a successful pilot phase, the IU eTexts Program moved into full production. As of March, 2018, it has served close to 200,000 students in over 9,000 course sections, and saved them more than $13 million in textbook costs. In this chapter, we explain the Indiana University eText model, the research efforts behind the program, support for faculty and students, and the factors behind the program’s success
Effects of E‐textbook Instructor Annotations on Learner Performance
With additional features and increasing cost advantages, e-textbooks are becoming a viable alternative to paper textbooks. One important feature offered by enhanced e-textbooks (e-textbooks with interactive functionality) is the ability for instructors to annotate passages with additional insights. This paper describes a pilot study that examines the effects of instructor e-textbook annotations on student learning as measured by multiple-choice and open-ended test items. Fifty-two college students in a business course were randomly assigned either a paper or an electronic version of a textbook chapter. Results show that the e-textbook group outperformed the paper textbook group on the open-ended test item, while both groups performed equally on the multiple-choice subject test. These results suggest that the instructional affordances that an interactive e-textbook provides may lead to higher-level learning
A comparison of electrochemical degradation of phenol on boron doped diamond and lead dioxide anodes
This work compares two electrode materials used to mineralize phenol contained in waste waters. Two disks covered with either boron doped diamond (BDD) or PbO2 were used as anodes in a one compartment flow cell under the same hydrodynamic conditions. Efficiencies of galvanostatic electrolyses are compared on the basis of measurements of Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD). Galvanostatic electrolyses were monitored by analysis of phenol and of its oxidation derivatives to evaluate the operating time needed for complete elimination of toxic aromatics. The experimental current efficiency is close to the theoretical value for the BDD electrode. Other parameters being equal, phenol species disappeared at the same rate using the two electrode materials but the BDD anode showed better efficiency to eliminate TOC and COD. Moreover, during the electrolysis less intermediates are formed with BDD compared to PbO2 whatever the current density. A comparison of energy consumption is given based on the criterion of 99% removal of aromatic compounds
The potential of human induced pluripotent stem cells for modelling diabetic wound healing in vitro
Examining students' use of, preferences for, and learning with e-textbooks
Paper presented at the 2019 American Educational Research Association Annual Meeting, Toronto, Canada.E-textbooks (e-texts) are becoming more available in higher education as they offer a cost advantage
and features that are intended to enhance teaching and learning. Although previous studies speak to
student experiences and preferences for e-texts, these studies are often limited in scope. The purpose
of this study is to understand student experiences with e-texts and the factors that drive their
preferences for textbook medium with a large-scale multi-institution data set. Findings indicate that e-text
use and preferences differ by a variety of student characteristics, most notably students' class level
and major field. In general, students who more frequently used the interactive features of e-texts felt
that their use of these tools contributed to their learning and interactions with others
A comparison of some random regression models for first lactation test day milk yields in jersey cows and estimating of genetic parameters
AnyStar: Domain randomized universal star-convex 3D instance segmentation
Star-convex shapes arise across bio-microscopy and radiology in the form of
nuclei, nodules, metastases, and other units. Existing instance segmentation
networks for such structures train on densely labeled instances for each
dataset, which requires substantial and often impractical manual annotation
effort. Further, significant reengineering or finetuning is needed when
presented with new datasets and imaging modalities due to changes in contrast,
shape, orientation, resolution, and density. We present AnyStar, a
domain-randomized generative model that simulates synthetic training data of
blob-like objects with randomized appearance, environments, and imaging physics
to train general-purpose star-convex instance segmentation networks. As a
result, networks trained using our generative model do not require annotated
images from unseen datasets. A single network trained on our synthesized data
accurately 3D segments C. elegans and P. dumerilii nuclei in fluorescence
microscopy, mouse cortical nuclei in micro-CT, zebrafish brain nuclei in EM,
and placental cotyledons in human fetal MRI, all without any retraining,
finetuning, transfer learning, or domain adaptation. Code is available at
https://github.com/neel-dey/AnyStar.Comment: Code available at https://github.com/neel-dey/AnySta
Dynamic Neural Fields for Learning Atlases of 4D Fetal MRI Time-series
We present a method for fast biomedical image atlas construction using neural
fields. Atlases are key to biomedical image analysis tasks, yet conventional
and deep network estimation methods remain time-intensive. In this preliminary
work, we frame subject-specific atlas building as learning a neural field of
deformable spatiotemporal observations. We apply our method to learning
subject-specific atlases and motion stabilization of dynamic BOLD MRI
time-series of fetuses in utero. Our method yields high-quality atlases of
fetal BOLD time-series with 5-7 faster convergence compared to
existing work. While our method slightly underperforms well-tuned baselines in
terms of anatomical overlap, it estimates templates significantly faster, thus
enabling rapid processing and stabilization of large databases of 4D dynamic
MRI acquisitions. Code is available at
https://github.com/Kidrauh/neural-atlasingComment: 6 pages, 2 figures. Accepted by Medical Imaging Meets NeurIPS 202
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
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