USG MATH 1113 Emporium: Insights from an Online Precalculus Course

The USG MATH 1113 Precalculus Emporium is a project to develop and implement an online, rigorous learning experience to improve student success with the additional goal of greater affordability. Based on initial experiences from Spring 2014, the MATH 1113 Precalculus Emporium was revised and continued in Fall 2014. This second pilot of the course involved a number of key revisions: - Online course orientation materials (overview of instructional technologies, academic honesty policies, time management plan, and orientation quiz), - Revised instructional model based involving a team of graduate teaching assistants, - Module balancing with a shift from four to five course assessments, - Revised weekly pacing and structure, - Additional video content and emphasis on online study halls. In this presentation aimed at postsecondary faculty in mathematics and online instructors, we discuss these revisions. We preview further developments, including a comprehensive online supplemental instruction program for Spring 2015

Can altering the distribution of organic matter in wetlands soils change methane emissions?

Forested mineral soil wetlands, found throughout the southeastern United States, store large amounts of carbon as woody biomass. Their anaerobic soil environments also make them hotspots for methanogenesis, leading to emissions of methane during soil respiration. Recent studies have suggested that at fine spatial scales (7.069 cm2), clumping of a labile carbon source, in dry soils, can result in lower microbial activity when compared to a uniformly distributed source. However, they also found in wetter soils (65% maximum water holding capacity), initial patterning of the carbon source didn’t affect microbial activity, presumably because the substrate was able to diffuse throughout the soil matrix. We investigated whether these results would hold for an inundated mineral wetland soil, Mhoon silt loam, at a larger spatial scale (1500 cm2) and with a natural wetland carbon source, bald cypress (Taxodium distichum) needles. We created three treatments: uniformly distributed needles (n=3), clumped needles (n=3), and no needles (n=3). Microbial activity is currently being measured, weekly, as the net CH4 flux. Microbial community composition (16S ribosomal RNA) was also measured after 2 months of incubation. At the end of our study needle mass loss will also be quantified for net decomposition. Initial results (first three months) showed that clumped and uniform needles did not have significantly different mean CH4 emissions. However, preliminary analysis of our microbial data suggests that the composition of microbes varied between patches of needles and no needles within mesocosms for both uniform and clumped treatments. This indicates that resources may not be diffusing through the entire mesocosm uniformly in inundated conditions. In the coming weeks, we will be detailing these patch dynamics by identifying the relative abundances of specific microbial groups, methanogens and methanotrophs. We will also continue to measure weekly net CH4 gas fluxes, as we hypothesize that the effect of resource patterning on microbial activity may vary as a function of resource lability. This work has implications for restoration practices (e.g., plantings, soil conditions) in forested mineral soil wetlands, a class of wetlands that have been historically impacted by drain and fill activities

Production of HO₂ and OH radicals from near-UV irradiated airborne TiO₂ nanoparticles

The production of gas-phase hydroperoxyl radicals, HO2, is observed directly from sub-micron airborne TiO2 nanoparticles (80% anatase and 20% rutile formulation) irradiated by 300 – 400 nm radiation. The rate of HO2 production as a function of O2 pressure follows Langmuir isotherm behaviour suggesting O2 is involved in the production of HO2 following its adsorption onto the surface of the TiO2 aerosol. Reduction of adsorbed O2 by photogenerated electrons is likely to be the initial step followed by reaction with a proton produced via oxidation of adsorbed water with a photogenerated hole. The rate of HO2 production decreased significantly over the range of relative humidities between 8.7 and 36.9 %, suggesting further adsorption of water vapour inhibits HO2 production. The adsorption equilibrium constants were calculated to be: KO2 = 0.27 ± 0.02 Pa-1 and KH2O = 2.16 ± 0.12 Pa-1 for RH = 8.7%, decreasing to KO2 = 0.18 ± 0.01 Pa-1 and KH2O = 1.33 ± 0.04 Pa-1 at RH = 22.1%. The increased coverage of H2O onto the TiO2 aerosol surface may inhibit HO2 production by decreasing the effective surface area of the TiO2 particle and lowering the binding energy of O2 on the aerosol surface, hence shortening its desorption lifetime. The yield of HO2 for atmospheric levels of O2 and normalised for surface area and light intensity was found to be k′prod = (3.64 ± 0.04) × 10-3 HO2 molecule photon-1 at RH = 8.7%. This yield decreased to k′prod = (1.97 ± 0.03) × 10-3 molecule photon-1 as the RH was increased to 22.1%. Using this value, the rate of production of HO2 from TiO2 surfaces under atmospheric conditions was estimated to be in the range 5x104 – 1x106 molecule cm-3 s-1 using observed surface areas of mineral dust at Cape Verde, and assuming a TiO2 fraction of 4.5%. For the largest loadings of dust in the troposphere, the rate of this novel heterogeneous production mechanism begins to approach that of HO2 production from the gas-phase reaction of OH with CO in unpolluted regions.The production of gas-phase OH radicals could only be observed conclusively at high aerosol surface areas, and was attributed to the decomposition of H2O2 at the surface by photogenerated electrons

Adaptive Signal Process Techniques for Extracting Craniate’s Electrocardiograms

This investigation introduces a robotized and non intrusive innovation utilizing a coordinated fetal transabdominal electrocardiogram framework and Doppler cardiogram (DCG) to distinguish fetal heart oddities. The Multiresolution wavelet investigation and Jensen-Shannon disparity (JSD) techniques were utilized to recognize the recurrence substance of the Doppler signs to be connected to the opening and shutting of the heart's valves (Aortic and mitral). For the everyday babies, PEP (Pre-discharge period), VET (Ventricular launch time), ICT (Isovolumic constriction time) and IVRT (Isovolumic unwinding time) were observed to be 75.0±11.9 (msec), 153.2±18.9 (msec), 50.0±15.9 (msec) and 69.6±9.7 (msec) separately. Then again, for hatchlings with heart inconsistencies, these planning interims were observed to be 89.0±10.3 (msec), 168.6±25.0 (msec), 52.2±17.2 (msec) and 51.6±13.7 (msec) separately. Punch, VET and IVRT values are altogether (p< zero.01) numerous between the two gatherings

Robust multicolor single photon emission from point defects in hexagonal boron nitride

© 2017 IEEE. We demonstrates engineering of quantum emitters in hBN multi-layers using either electron beam irradiation or annealing. The defects exhibit a broad range of multicolor room-temperature single photon emissions across the visible and the near-infrared ranges

Cardiovascular magnetic resonance in cardiac sarcoidosis with MR conditional pacemaker in situ

Cardiovascular implantable electronic devices represent important limitations to magnetic resonance imaging (MRI). Recently, MRI-conditional dual chamber pacemakers and leads have become available. We describe a case of a patient with neuro-sarcoidosis presenting with diplopia and hydrocephalus requiring an MRI-conditional programmable ventriculo-peritoneal shunt, who developed complete heart block. In view of the ongoing need for neuro-imaging, MRI-conditional dual chamber pacemaker and leads were implanted. Cardiac and brain MRI were requested to guide immunosupression. Overall the scans demonstrated stable neurological disease, but confirmed cardiac sarcoid, with oedema on T2 weighted images suggesting active disease and extensive sub-endocardial late gadolinium enhancement, including the basal septum. This case illustrates why sarcoid patients who develop bradyarrhythmias should ideally have an MRI-conditional pacing system

Scans for signatures of selection in Russian cattle breed genomes reveal new candidate genes for environmental adaptation and acclimation

Domestication and selective breeding has resulted in over 1000 extant cattle breeds. Many of these breeds do not excel in important traits but are adapted to local environments. These adaptations are a valuable source of genetic material for efforts to improve commercial breeds. As a step toward this goal we identified candidate regions to be under selection in genomes of nine Russian native cattle breeds adapted to survive in harsh climates. After comparing our data to other breeds of European and Asian origins we found known and novel candidate genes that could potentially be related to domestication, economically important traits and environmental adaptations in cattle. The Russian cattle breed genomes contained regions under putative selection with genes that may be related to adaptations to harsh environments (e.g., AQP5, RAD50, and RETREG1). We found genomic signatures of selective sweeps near key genes related to economically important traits, such as the milk production (e.g., DGAT1, ABCG2), growth (e.g., XKR4), and reproduction (e.g., CSF2). Our data point to candidate genes which should be included in future studies attempting to identify genes to improve the extant breeds and facilitate generation of commercial breeds that fit better into the environments of Russia and other countries with similar climates

A medical device-grade T1 and ECV phantom for global T1 mapping quality assurance - the T1_1 Mapping and ECV Standardization in cardiovascular magnetic resonance (T1MES) program

$\textbf{Background:}$ T$_1$ mapping and extracellular volume (ECV) have the potential to guide patient care and serve as surrogate end-points in clinical trials, but measurements differ between cardiovascular magnetic resonance (CMR) scanners and pulse sequences. To help deliver T$_1$ mapping to global clinical care, we developed a phantom-based quality assurance (QA) system for verification of measurement stability over time at individual sites, with further aims of generalization of results across sites, vendor systems, software versions and imaging sequences. We thus created T1MES: The T1 Mapping and ECV Standardization Program. $\textbf{Methods:}$ A design collaboration consisting of a specialist MRI small-medium enterprise, clinicians, physicists and national metrology institutes was formed. A phantom was designed covering clinically relevant ranges of T$_1$ and T$_2$ in blood and myocardium, pre and post-contrast, for 1.5 T and 3 T. Reproducible mass manufacture was established. The device received regulatory clearance by the Food and Drug Administration (FDA) and Conformité Européene (CE) marking. $\textbf{Results:}$ The T1MES phantom is an agarose gel-based phantom using nickel chloride as the paramagnetic relaxation modifier. It was reproducibly specified and mass-produced with a rigorously repeatable process. Each phantom contains nine differently-doped agarose gel tubes embedded in a gel/beads matrix. Phantoms were free of air bubbles and susceptibility artifacts at both field strengths and T$_1$ maps were free from off-resonance artifacts. The incorporation of high-density polyethylene beads in the main gel fill was effective at flattening the $B_1$ field. T$_1$ and T$_2$ values measured in T1MES showed coefficients of variation of 1 % or less between repeat scans indicating good short-term reproducibility. Temperature dependency experiments confirmed that over the range 15-30 °C the short-T$_1$ tubes were more stable with temperature than the long-T$_1$ tubes. A batch of 69 phantoms was mass-produced with random sampling of ten of these showing coefficients of variations for T$_1$ of 0.64 ± 0.45 % and 0.49 ± 0.34 % at 1.5 T and 3 T respectively. $\textbf{Conclusion:}$ The T1MES program has developed a T$_1$ mapping phantom to CE/FDA manufacturing standards. An initial 69 phantoms with a multi-vendor user manual are now being scanned fortnightly in centers worldwide. Future results will explore T$_1$ mapping sequences, platform performance, stability and the potential for standardization.This project has been funded by a European Association of Cardiovascular Imaging (EACVI part of the ESC) Imaging Research Grant, a UK National Institute of Health Research (NIHR) Biomedical Research Center (BRC) Cardiometabolic Research Grant at University College London (UCL, #BRC/ 199/JM/101320), and a Barts Charity Research Grant (#1107/2356/MRC0140). G.C. is supported by the National Institute for Health Research Rare Diseases Translational Research Collaboration (NIHR RD-TRC) and by the NIHR UCL Hospitals Biomedical Research Center. J.C.M. is directly and indirectly supported by the UCL Hospitals NIHR BRC and Biomedical Research Unit at Barts Hospital respectively. This work was in part supported by an NIHR BRC award to Cambridge University Hospitals NHS Foundation Trust and NIHR Cardiovascular Biomedical Research Unit support at Royal Brompton Hospital London UK

Identification of myocardial diffuse fibrosis by 11 heartbeat MOLLI T1 mapping: averaging to improve precision and correlation with collagen volume fraction

Objectives: Our objectives involved identifying whether repeated averaging in basal and mid left ventricular myocardial levels improves precision and correlation with collagen volume fraction for 11 heartbeat MOLLI T1 mapping versus assessment at a single ventricular level. Materials and methods: For assessment of T1 mapping precision, a cohort of 15 healthy volunteers underwent two CMR scans on separate days using an 11 heartbeat MOLLI with a 5(3)3 beat scheme to measure native T1 and a 4(1)3(1)2 beat post-contrast scheme to measure post-contrast T1, allowing calculation of partition coefficient and ECV. To assess correlation of T1 mapping with collagen volume fraction, a separate cohort of ten aortic stenosis patients scheduled to undergo surgery underwent one CMR scan with this 11 heartbeat MOLLI scheme, followed by intraoperative tru-cut myocardial biopsy. Six models of myocardial diffuse fibrosis assessment were established with incremental inclusion of imaging by averaging of the basal and mid-myocardial left ventricular levels, and each model was assessed for precision and correlation with collagen volume fraction. Results: A model using 11 heart beat MOLLI imaging of two basal and two mid ventricular level averaged T1 maps provided improved precision (Intraclass correlation 0.93 vs 0.84) and correlation with histology (R2 = 0.83 vs 0.36) for diffuse fibrosis compared to a single mid-ventricular level alone. ECV was more precise and correlated better than native T1 mapping. Conclusion: T1 mapping sequences with repeated averaging could be considered for applications of 11 heartbeat MOLLI, especially when small changes in native T1/ECV might affect clinical management