ADVANCING THE DEVELOPMENT OF ADDITIVELY MANUFACTURED SEQUENTIALLY CURED INTERPENETRATING POLYMER NETWORKS

Recently vat photopolymerization (VPP), a type of additive manufacturing (AM), has the potential to be used for a variety of commercial and military applications due to the ability to make custom parts rapidly and with complex geometries. Many commercially available photopolymerizable resins consist of (meth)acrylate and epoxy functionality to ensure rapid cure time and minimal shrinkage. Today, researchers continue to find the optimal balance of (meth)acrylate/epoxy functionality in unique formulations and network configurations, such as interpenetrating polymer networks (IPN)s, to enhance processibility and the quality of the final printed part. This work explores the structure-property relationships of a set of VPP resins synthesized from select starting materials in addition to improving the one-pot, two-step reaction methodology that has been employed by the Sustainable Materials Research Laboratory (SMRL) at Rowan University. Epoxy-methacrylate IPNs were prepared via a sequentially cured AM technique and subsequently evaluated for their thermal and mechanical properties. Through the incorporation of higher degrees of aliphatic character, the 3D printed IPNs yield an enhancement in toughness while maintaining thermal properties. Resultant IPNs were found to maintain glass transition temperatures above 130 ⁰C (tan δ) and increase fracture energies by more than 160%

Exploring Teachers\u27 Read-Aloud Book Selections: What Drives the Decision

Reading aloud is a common classroom practice that has many cognitive and affective benefits for students. Early childhood teachers conduct read-aloud events in classrooms across the country on a daily basis. A read-aloud event could not occur without the intentional selection of a book. This exploratory, sequential mixed method study explored the current use and frequency of read-alouds in K-2 classrooms. Specifically, the study sought to better understand teachers\u27 decision-making when choosing books to read aloud. This mixed method study occurred in two sequential phases: a qualitative phase followed by a quantitative phase. During the first phase, fifteen teachers were asked to document their read-aloud events in the classroom and share their rationale for selecting the books they chose to read. These teachers were then interviewed to learn more about their decision-making. Based on the findings of Phase I, a survey was developed and disseminated nationally. A total of 259 K-2 teachers from across the county responded to the survey during Phase II, which further explored the findings of the first phase. The findings reveal that 90% of teachers report reading aloud in K-2 classrooms several times a week or more. While many teachers follow specific reading curricula required by their school or district, 63.9% of them choose additional books to read aloud in the classroom. While teachers predominately expressed that the purpose of reading aloud was to develop a love of reading, their actual selection of the book was determined by how the book would help them teach or develop skills. Teachers shared many different modes for acquiring the books they use in their classrooms with the most common being the use of Scholastic Book Club, with 76.4% noting that they spend their personal money to build their classroom libraries. In selecting books for read-aloud, these teachers often make choices based on their own preferences, or on their assumptions of what their students like to hear. Teachers in this study reported a strong inclination to read fiction texts instead of informational texts, stating that they believed this is what their students wanted to hear. The act of reading aloud has been explored in great detail in the literature. With much support from the literature for reading aloud to students, this study explored the lesser-studied half of the read-aloud equation – the book selection process. This study attempted to better understand the decisions teachers make prior to reading aloud, decisions that greatly impact students\u27 outcomes

Development and application of an antibiotic spectrum index for benchmarking antibiotic selection patterns across hospitals

Standard metrics for antimicrobial use consider volume but not spectrum of antimicrobial prescribing. We developed an antibiotic spectrum index (ASI) to classify commonly used antibiotics based on activity against important pathogens. The application of this index to hospital antibiotic use reveals how this tool enhances current antimicrobial stewardship metrics.Infect Control Hosp Epidemiol 2017;38:993–997</jats:p

MISSING DATA AND MEASUREMENT ERROR: ANALYTIC APPROACHES FOR OBSERVATIONAL STUDIES WITH EXAMPLES FROM PREGNANCY OUTCOMES RESEARCH

Observational research to improve pregnancy outcomes faces methodological challenges that limit accurate and actionable evidence. The objective of this dissertation was to examine analytic approaches to address the common challenges of measurement error and missing data.In Aim 1, we developed and validated standardization (g-computation) estimators that leverage external validation data to account for outcome misclassification. To account for measurement error, external validation data are used to estimate misclassification probabilities (i.e., sensitivity and specificity). When the validation data are external, the estimated misclassification probabilities may need to be transported from the validation to the target population. If there are variables related to misclassification whose distribution differ between the validation and target, these probabilities are not immediately transportable. We introduce estimators that account for these variables in order to transport. For estimation, we used M-estimation. In simulation, these estimators were unbiased when assumptions were met and confidence intervals had appropriate coverage. We used these estimators in an applied example to estimate the effect of maternal HIV infection on preterm birth. Estimates accounting for outcome misclassification were notably different from the naïve analysis.In Aim 2, we illustrated implementation and examined the performance of a novel weighted estimator to address nonmonotone missingness. In simulation, we compared performance to complete case analysis and multiple imputation by chained equations. Regardless of the missing data approach, we used weighting to address confounding. When complete case analysis was biased, weighting and imputation were unbiased, except when data were missing not at random. Imputation was more precise as sample size and percent exposed declined; otherwise imputation and weighting were similarly precise. Imputation was less computationally efficient than weighting. We used these estimators in an applied example to estimate the effect of maternal anemia on preterm birth risk, where estimates were similar across approaches.Measurement error and missing data are often overlooked yet they can produce substantial bias. This dissertation examined novel analytic tools to address these issues. Our work makes these tools accessible to other epidemiologists in order to advance research to improve pregnancy outcomes and public health more broadly.Doctor of Philosoph

Variability in antifungal and antiviral use in hospitalized children

We analyzed antifungal and antiviral prescribing among high-risk children across freestanding children’s hospitals. Antifungal and antiviral days of therapy varied across hospitals. Benchmarking antifungal and antiviral use and developing antimicrobial stewardship strategies to optimize use of these high cost agents is needed.Infect Control Hosp Epidemiol2017;38:743–746</jats:p

The Field-Testing of a Novel Integrated Mapping Protocol for Neglected Tropical Diseases

Neglected tropical diseases (NTDs) cause significant physical debilitation, lowered economic productivity, and social ostracism for afflicted individuals. Five NTDs with available preventive chemotherapy: lymphatic filariasis (LF), trachoma, schistosomiasis, onchocerciasis and the three soil-transmitted helminths (STH); have been targeted for control or elimination, but resource constraints in endemic countries have impeded progress toward these goals. We have developed an integrated mapping protocol, Integrated Threshold Mapping (ITM) for use by Ministries of Health to decide where public health interventions for NTDs are needed. We compared this protocol to the World Health Organizations disease-specific mapping protocols in Mali and Senegal. Results from both methodologies indicated the same public health interventions for trachoma, LF and STH, while the ITM methodology resulted in a more targeted intervention for schistosomiasis. Our study suggests that the integrated methodology, which is also less expensive and logistically more feasible to implement, could replace disease-specific mapping protocols in resource-poor NTD-endemic countries

Restoration of SMN in Schwann cells reverses myelination defects and improves neuromuscular function in spinal muscular atrophy

Spinal muscular atrophy (SMA) is a neuromuscular disease caused by low levels of SMN protein, primarily affecting lower motor neurons. Recent evidence from SMA and related conditions suggests that glial cells can influence disease severity. Here, we investigated the role of glial cells in the peripheral nervous system by creating SMA mice selectively overexpressing SMN in myelinating Schwann cells (Smn(−/−);SMN2(tg/0);SMN1(SC)). Restoration of SMN protein levels restricted solely to Schwann cells reversed myelination defects, significantly improved neuromuscular function and ameliorated neuromuscular junction pathology in SMA mice. However, restoration of SMN in Schwann cells had no impact on motor neuron soma loss from the spinal cord or ongoing systemic and peripheral pathology. This study provides evidence for a defined, intrinsic contribution of glial cells to SMA disease pathogenesis and suggests that therapies designed to include Schwann cells in their target tissues are likely to be required in order to rescue myelination defects and associated disease symptoms

Near Infrared Spectra and Intrinsic Luminosities of Candidate Type II Quasars at 2 < z < 3.4

We present JHK near-infrared (NIR) spectroscopy of 25 candidate Type II quasars selected from the Sloan Digital Sky Survey, using Triplespec on the Apache Point Observatory 3.5m telescope, FIRE at the Magellan/Baade 6.5m telescope, and GNIRS on Gemini. At redshifts of 2 < z < 3.4, our NIR spectra probe the rest-frame optical region of these targets, which were initially selected to have strong lines of CIV and Ly alpha, with FWHM<2000 km/s from the SDSS pipeline. We use the [OIII]5007 line shape as a model for the narrow line region emission, and find that \halpha\ consistently requires a broad component with FWHMs ranging from 1000 to 7500 km/s. Interestingly, the CIV lines also require broad bases, but with considerably narrower widths of 1000 to 4500 km/s. Estimating the extinction using the Balmer decrement and also the relationship in lower-z quasars between rest equivalent width and luminosity in the [OIII] line, we find typical A_V values of 0-2 mag, which naturally explain the attenuated CIV lines relative to Halpha. We propose that our targets are moderately obscured quasars. We also describe one unusual object with three distinct velocity peaks in its [OIII] spectrum.Comment: Accepted for publication in ApJ, 18 pages, 14 figure

SWI/SNF-like chromatin remodeling factor Fun30 supports point centromere function in S. cerevisiae

Budding yeast centromeres are sequence-defined point centromeres and are, unlike in many other organisms, not embedded in heterochromatin. Here we show that Fun30, a poorly understood SWI/SNF-like chromatin remodeling factor conserved in humans, promotes point centromere function through the formation of correct chromatin architecture at centromeres. Our determination of the genome-wide binding and nucleosome positioning properties of Fun30 shows that this enzyme is consistently enriched over centromeres and that a majority of CENs show Fun30-dependent changes in flanking nucleosome position and/or CEN core micrococcal nuclease accessibility. Fun30 deletion leads to defects in histone variant Htz1 occupancy genome-wide, including at and around most centromeres. FUN30 genetically interacts with CSE4, coding for the centromere-specific variant of histone H3, and counteracts the detrimental effect of transcription through centromeres on chromosome segregation and suppresses transcriptional noise over centromere CEN3. Previous work has shown a requirement for fission yeast and mammalian homologs of Fun30 in heterochromatin assembly. As centromeres in budding yeast are not embedded in heterochromatin, our findings indicate a direct role of Fun30 in centromere chromatin by promoting correct chromatin architecture

Forest fire threatens global carbon sinks and population centres under rising atmospheric water demand

Levels of fire activity and severity that are unprecedented in the instrumental record have recently been observed in forested regions around the world. Using a large sample of daily fire events and hourly climate data, here we show that fire activity in all global forest biomes responds strongly and predictably to exceedance of thresholds in atmospheric water demand, as measured by maximum daily vapour pressure deficit. The climatology of vapour pressure deficit can therefore be reliably used to predict forest fire risk under projected future climates. We find that climate change is projected to lead to widespread increases in risk, with at least 30 additional days above critical thresholds for fire activity in forest biomes on every continent by 2100 under rising emissions scenarios. Escalating forest fire risk threatens catastrophic carbon losses in the Amazon and major population health impacts from wildfire smoke in south Asia and east Africa.he authors acknowledge the New South Wales Government’s Department of Planning, Industry & Environment for providing funds to support this research via the NSW Bushfire Risk Management Research Hub. We acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modelling groups for producing and making available their model output. For CMIP the U.S. Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. Some of the analysis was carried out on the National Computational Infrastructure (NCI) which is supported by the Australian Commonwealth Government