Browsing by Subject "diffusion"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Becoming an Agile Change Conductor
    (Frontiers, 2022) Mehta, Jade; Aalsma, Matthew C.; O'Brien, Andrew; Boyer, Tanna J.; Ahmed, Rami A.; Summanwar, Diana; Boustani, Malaz; Family Medicine, School of Medicine
    Background: It takes decades and millions of dollars for a new scientific discovery to become part of clinical practice. In 2015, the Center for Health Innovation & Implementation Science (CHIIS) launched a Professional Certificate Program in Innovation and Implementation Sciences aimed at transforming healthcare professionals into Agile Change Conductors capable of designing, implementing, and diffusing evidence-based healthcare solutions. Method: In 2022, the authors surveyed alumni from the 2016–2021 cohorts of the Certificate Program as part of an educational quality improvement inquiry and to evaluate the effectiveness of the program. Results: Of the 60 alumni contacted, 52 completed the survey (87% response rate) with 60% of graduates being female while 30% were an under-represented minority. On a scale from 1 to 5, the graduates agreed that the certificate benefited their careers (4.308 with a standard deviation (SD) of 0.612); expanded their professional network (4.615, SD of 0.530); and had a large impact on the effectiveness of their leadership (4.288, SD of 0.667), their change management (4.365, SD of 0.742), and their communication (4.392, SD of 0.666). Graduates claimed to use Agile Processes (Innovation, Implementation, or Diffusion), storytelling, and nudging weekly. On a scale from 0 to 10 where 10 indicates reaching a mastery, the average score for different Agile competencies ranged from 5.37 (SD of 2.80) for drafting business proposals to 7.77 (SD of 1.96) for self-awareness. For the 2020 and 2021 cohorts with existing pre and post training competency data, 22 of the 26 competencies saw a statistically significant increase. Conclusion: The Graduate Certificate has been able to create a network of Agile Change Conductors competent to design, implement, and diffuse evidence-based care within the healthcare delivery system. Further improvements in building dissemination mastery and program expansion initiatives are advised.
  • Thumbnail Image
    Item
    A data-driven alternative to the fractional Fokker–Planck equation
    (IOP, 2015-07) Pressé, Steve; Department of Physics, School of Science
    Anomalous diffusion processes are ubiquitous in biology and arise in the transport of proteins, vesicles and other particles. Such anomalously diffusive behavior is attributed to a number of factors within the cell including heterogeneous environments, active transport processes and local trapping/binding. There are a number of microscopic principles?such as power law jump size and/or waiting time distributions?from which the fractional Fokker?Planck equation (FFPE) can be derived and used to provide mechanistic insight into the origins of anomalous diffusion. On the other hand, it is fair to ask if other microscopic principles could also have given rise to the evolution of an observed density profile that appears to be well fit by an FFPE. Here we discuss another possible mechanistic alternative that can give rise to densities like those generated by FFPEs. Rather than to fit a density (or concentration profile) using a solution to the spatial FFPE, we reconstruct the profile generated by an FFPE using a regular FPE with a spatial and time-dependent force. We focus on the special case of the spatial FFPE for superdiffusive processes. This special case is relevant to, for example, active transport in a biological context. We devise a prescription for extracting such forces on synthetically generated data and provide an interpretation to the forces extracted. In particular, the time-dependence of forces could tell us about ATP depletion or changes in the cell's metabolic activity. Modeling anomalous behavior with normal diffusion driven by these effective forces yields an alternative mechanistic picture that, ultimately, could help motivate future experiments.
  • Thumbnail Image
    Item
    Diffusion, Perfusion, and Histopathologic Characteristics of Desmoplastic Infantile Ganglioglioma.
    (EduRad Publishing, 2016-07) Ho, Chang Y.; Gener, Melissa; Bonnin, Jose; Kralik, Stephen F.; Department of Radiology and Imaging Sciences, IU School of Medicine
    We present a case series of a rare tumor, the desmoplastic infantile ganglioglioma (DIG) with MRI diffusion and perfusion imaging quantification as well as histopathologic characterization. Four cases with pathologically-proven DIG had diffusion weighted imaging (DWI) and two of the four had dynamic susceptibility contrast imaging. All four tumors demonstrate DWI findings compatible with low-grade pediatric tumors. For the two cases with perfusion imaging, a higher relative cerebral blood volume was associated with higher proliferation index on histopathology for one of the cases. Our results are discussed in conjunction with a literature review.
  • Thumbnail Image
    Item
    Generating Acoustic Diffuser Arrays with Shape Grammars
    (Georgia Tech, 2019-04) Dessi-Olive, Jonathan; Hsu, Timothy; Medicine, School of Medicine
    This paper presents research on a rule-based approach to designing creative acoustic diffuser arrays. A shape grammar-influenced design method is specified that uses shape rules to recursively design arrays of quadratic residue diffusers (QRD) in ways that are neither mechanical nor deterministic.
  • Thumbnail Image
    Item
    Lower transfer factor of the lung for carbon monoxide in women with a patent foramen ovale
    (The Physiological Society, 2022-03-01) Schallerer, Annalisa E.; Duke, Joseph W.; Speros, Julia P.; Mangum , Tyler S.; Norris, H. Cameron; Beasley, Kara M.; Laurie, Steven S.; Elliott, Jonathan E.; Davis, James T.; Lovering, Andrew T.; Medicine, School of Medicine
    New Findings What is the central question of this study? Do individuals with a patent foramen ovale (PFO+) have a lower lung transfer factor for carbon monoxide than those without (PFO−)? What is the main finding and its importance? We found a lower rate constant for carbon monoxide uptake in PFO+ compared with PFO− women, which was physiologically relevant (≥0.5 z-score difference), but not for PFO+ versus PFO− men. This suggests that factors independent of the PFO are responsible for our findings, possibly inherent structural differences in the lung. The transfer factor of the lung for carbon monoxide (TLCO) measure assumes that all cardiac output flows through the pulmonary circuit. However, right-to-left blood flow through a shunt can result in a lower transfer factor than predicted. A patent foramen ovale (PFO) is a potential source of right-to-left shunt that is present in ∼35% of the population, but the effect of PFO on TLCO is unknown. We sought to determine the effect of PFO on the TLCO. We conducted a retrospective analysis of TLCO data from 239 (101 women) participants. Anthropometrics and lung function, including spirometry, plethysmography and TLCO, were compiled from our previously published work. Women, but not men, with a PFO had a significantly lower TLCO and rate constant for carbon monoxide uptake (KCO) (percentage of predicted and z-score) than women without a PFO. Women and men with a PFO had normal alveolar volumes that did not differ from those without a PFO. Correcting the data for haemoglobin in a subset of subjects did not change the results (n = 58; 25 women). The lower KCO in women with versus without a PFO was physiologically relevant (≥0.5 z-score difference). There was no effect of PFO in men. This suggests that factors independent of the PFO are responsible for our findings, possibly inherent structural differences in the lung.
  • Thumbnail Image
    Item
    Molecular Dynamics Simulation of Electrical Resistivity in Sintering Process of Nanoparticle Silver Inks
    (Elsevier, 2016-12) Zhang, Yi; Wu, Linmin; Guo, Xingye; Jung, Yeon-Gil; Zhang, Jing; Department of Mechanical Engineering, School of Engineering and Technology
    A molecular dynamics (MD) model is developed to simulate low temperature sintering of silver nanoparticles and resultant resistivity. Due to the high surface to volume ratio, nanoparticle silver inks can sinter at low thermal curing temperatures, which are used in intense pulsed light (IPL) sintering process. In this study, the configurational change of nanoparticle silver during sintering is studied using the MD model. Then the resultant electric resistivity is calculated using the Reimann-Weber formula. The simulation results show that the resistivity decreases rapidly in the initial sintering stage, due to the fast neck formation and growth. Additionally, the predicted temperature-dependent resistivity evolutions are in good agreement with both experimental measurements and analytical sintering model, indicating that the resistivity decreases with increasing sintering temperature. The model provides a design tool for optimizing IPL process.
  • Thumbnail Image
    Item
    Strengths and Weaknesses of Recently Engineered Red Fluorescent Proteins Evaluated in Live Cells Using Fluorescence Correlation Spectroscopy
    (MDPI, 2013-10-14) Siegel, Amanda P.; Baird, Michelle A.; Davidson, Michael W.; Day, Richard N.; Cellular and Integrative Physiology, School of Medicine
    The scientific community is still looking for a bright, stable red fluorescent protein (FP) as functional as the current best derivatives of green fluorescent protein (GFP). The red FPs exploit the reduced background of cells imaged in the red region of the visible spectrum, but photophysical short comings have limited their use for some spectroscopic approaches. Introduced nearly a decade ago, mCherry remains the most often used red FP for fluorescence correlation spectroscopy (FCS) and other single molecule techniques, despite the advent of many newer red FPs. All red FPs suffer from complex photophysics involving reversible conversions to a dark state (flickering), a property that results in fairly low red FP quantum yields and potential interference with spectroscopic analyses including FCS. The current report describes assays developed to determine the best working conditions for, and to uncover the shortcoming of, four recently engineered red FPs for use in FCS and other diffusion and spectroscopic studies. All five red FPs assayed had potential shortcomings leading to the conclusion that the current best red FP for FCS is still mCherry. The assays developed here aim to enable the rapid evaluation of new red FPs and their smooth adaptation to live cell spectroscopic microscopy and nanoscopy.