Johns Hopkins Research Data Repository
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553 research outputs found
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Data associated with publication "Analytical Platform to Characterize Dopant Solution Concentrations, Charge Carrier Densities in Films and Interfaces, and Physical Diffusion in Polymers Utilizing Remote Field-Effect Transistors"
No full textCharacterizing doping effects in a conductive polymer and physical diffusion in a passive polymer were performed using a remote-gate field-effect transistor (RG FET) detection system that was able to measure the electrical potential perturbation of a polymer film coupled to the gate of a silicon FET. Poly(3-hexylthiophene) (P3HT) film doped using various concentrations of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) solutions imposed additional positive potentials on the P3HT RG, resulting in a lower threshold voltage (V_th) on the n-channel silicon FET. Changes in V_th were related to the induced hole concentrations and hole mobility in P3HT films by using our V_th shifting model for the RG FET. We discovered that the electron-donating P3HT and even inorganic materials, indium tin oxide and gold, showed similar electrical potential perturbations dependent on the concentration of F4TCNQ in overlying solutions as the dopant radical anions maximally covered the surfaces. This suggests that there are limited electroactive sites for F4TCNQ binding on electron donor surfaces which results in a similar number of positive charges in film materials forming dipoles with the F4TCNQ radical counteranions. The effect of electron acceptors such as 7,7,8,8-tetracyanoquinodimethane and tetracyanoethylene was compared with that of F4TCNQ in terms of V_th shift using our analytical tool, with differences attributed to acceptor size and reduction potential. Meanwhile, this FET analysis tool offered a means of monitoring the physical diffusion of small molecules, exemplified by F4TCNQ, in the passive polymer polystyrene, driven by concentration gradients. The technique allows for nondestructive, nonspectroscopic, ambient characterization of electron donor-acceptor interactions at surfaces
Data and software associated with publication "Sensory Cues Modulate Smooth Pursuit and Active Sensing Movements"
No full textThis project includes data from experiments conducted with weakly electric fish Eigenmannia virescens while tracking a moving refuge. In this project we studied how the sensory cues in the environment modulate the smooth pursuit and active sensing movements of Eigenmannia. To examine this, we altered the visual and electrosensory cues for refuge tracking and measured the fore-aft movements of the fish. Specifically, we altered the length and structure of the refuge and performed experiments with light and in complete darkness. The data were collected in the LIMBS laboratory at JHU. The project includes raw data files for each experiment conducted with the fish, processed data files, and MATLAB scripts for data analysis and reproduction of the result figures of Uyanik and Stamper et al., Frontiers in Behavioral Neuroscience (Special Issue on Active Sensing), 2019
Data associated with A Comprehensive Snapshot of Tuberculosis Transmission in an Urban Ugandan Community (STOMP-TB Study)
No full textLack of access to health facilities may be a barrier to initiating and completing tuberculosis (TB) treatment. We aimed to evaluate whether distance from residence to health facility is associated with treatment outcomes. We conducted a retrospective cohort study of all patients initiating TB treatment at six health facilities in Kampala from 2014-2016. Six facilities (one public and five private) whose catchment areas include the parishes of Kisugu and Wabigalo were selected and data from all patients receiving treatment at these facilities were abstracted from routinely used TB registers. This data was used to investigate associations between distance to treating facility and unfavorable TB treatment outcomes
Coded quotations for codes relevant to the paper “Bringing fear into focus: The intersections of HIV and masculine gender norms in Côte d’Ivoire”
No full textUsing data from 73 in-depth interviews and 28 focus group discussions with 227 Ivoirian men collected between November and December 2016 across three urban sites, this qualitative research study aimed to explore the role masculinity plays in men’s engagement in the HIV care continuum in Côte d’Ivoire. The data posted here is a subset of the larger dataset and includes coded quotations (deidentified) relevant to the topic of the manuscript
Data associated with "Effects of trifluoromethyl substituents on interfacial and bulk polarization of polystyrene gate dielectrics"
No full textFrom the publication abstract: The ability to control the bulk and interfacial polarization of dielectric polymers is important to their application in organic electronics. We examine the effect of the trifluoromethyl substituent on poly(3-trifluoromethylstyrene) (P3TFMS) as compared to unsubstituted polystyrene (PS) on the I-V relationships of pentacene-based organic field-effect transistors (OFETs). Single- and double-layered films of these polymers were used, with lower layers crosslinked through vinylbenzocyclobutene comonomers before deposition of upper layers. Control experiments verified that the electronic effect of the crosslinking was negligible. We found that the TFM substituent markedly and independently affected both the initial threshold voltage Vth and the nonvolatile, shifted Vth observed after the application of static gate voltage, depending on its position adjacent or apart from the pentacene. The trifluoromethyl-bearing polymers exhibited significantly lower magnitude initial threshold voltages (Vth,i of ca. −17 V for P3TFMS compared to −35 V for PS), large threshold voltage shifts after charging by the application of static electric fields (ΔVth of ca. 32 V for P3TFMS and 17 V for PS), and greater stability of the ΔVth under repeated charge/discharge cycles. These results are consistent with P3TFMS having fewer interfacial trap states but more stable bulk trap states. The results are applicable to organo-electronic systems such as piezoelectrics for energy harvesting and nonvolatile OFETs such as memory, sensing, and logic elements
Data associated with 'Development of the Consumer Attitudes Towards Healthcare Scale'
No full textData supporting construction of a scale entitled the Consumerist Attitudes in Healthcare Scale. We used a literature-informed strategy to develop the Consumerist Attitudes towards Healthcare Scale, drawing items from related scales if these items represented the construct of consumerism. We conducted a targeted literature search to identify conceptual models that describe the patient as a consumer of healthcare. We also identified existing scales and questionnaires as a supply of items for inclusion. From the identified literature, we extracted a list of attitudes, preferences, and expectations for inclusion in our initial survey. We surveyed a nationally representative US population with a 45 item questionnaire that used 5-point Likert responses to assess consumeristic attitudes. We generated a polychoric correlation matrix and did exploratory factor analysis using a principal components solution. We sent the resulting scale to additional respondents twice for repeatability testing. We then surveyed a new nationally representative population with this consumeristic attitudes scale plus 2 additional existent scales for testing of concordance and discordance.
The confirmatory factor analysis on the new results was very similar to the initial survey results supporting a 3-factor, 11 item scale. The three factors might best be described as 1) feeling self-efficacious in health care interactions; 2) preferring to be the decision maker; 3) expressing confidence in knowledge about the health care system. On a five point scale (with 1 being most consumeristic), the respondents had mean score of 1.9 (SD 0.53).The scale was correlated modestly with the Medical Maximizer/Minimizer Scale (rho=0.25, p<0.0001) and was not correlated with the Attitudes toward Technology Scale (rho=0.07, p=0.17), which is what we anticipated. The Cronbach’s alpha for the full scale was 0.84. Exploratory subgroup analysis suggested that younger patients have the least consumeristic attitudes
Head CT Scans associated with 'Validated automatic brain extraction of head CT images'
No full textThe data consists of 35 different subject's non-contrast CT scan, with 2 subjects having 2 scans but every other subject having one scan (in tarballs). One subject additionally has 2 scans, but from the same time point, but with different convolution kernels. Each scan has at least one reader's manual segmentation of the image to delineate the mask of the brain areas (including cerebrospinal fluid (CSF)).
The data are from the Minimally-Invasive Surgery plus rt-PA for Intracerebral hemorrhage Evacuation (MISTIE) Phases II and III clinical trials the Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage (CLEAR) Phase III clinical trial.
Each tarball contains a series of NIfTI (Neuroimaging Informatics Technology Initiative) files. These files can be read using common tools such as ITK-SNAP (http://www.itksnap.org/pmwiki/pmwiki.php), Mango (http://ric.uthscsa.edu/mango/), or Papaya (http://ric.uthscsa.edu/mango/papaya.html). Each image has manual segmentation from 2 different readers which is a binary image delineating the brain and an automated estimate of the brain by the method proposed in the paper below
Data associated with the manuscript by Zhang et al. The impact of strain-specific biofilm properties on the retention of microplastic in stormwater biofilters
No full textStormwater biofilters have variable colloidal particle removal efficiencies that may be due to different characteristics of microorganisms colonizing them during normal operation. Little is known about how naturally occurring bacteria modify the surface properties of the filtration media, or how these modifications affect colloidal microplastic removal. We used simulated infiltration through model sand columns to study the impact of colonizing microorganisms on the retention of model colloidal microplastic particles, carboxyl-modified-latex (CML) beads. Four naturally occurring stormwater bacterial strains inhibited bead retention compared to a clean bed in a cell-density independent manner, while a model biofilm forming microorganism (Pseudomonas aeruginosa) enhanced retention likely due to physical straining. Atomic force microscopy (AFM) was applied to analyze interaction energy between CML and each bacterial strain biofilm surface. We found that interaction energy between CML and each strain was significantly different, and we propose that changes in the CML bead retention behavior are related to these differences. In particular, we propose that larger repulsive energy generated by some biofilms prevents close contact of CML to surface required for adhesion. Our evidence suggests that extra-cellular polymeric substances modify media surfaces to alter both adhesion and repulsion of beads. Overall, the work demonstrates how AFM can be used to characterize colloidal-collector interactions and provide insights into mechanisms that could be exploited to improve EIS design and operation. The purpose of this collection is to make available to the public the material necessary to validate the research findings
Data Associated with publication "Vertical transport of sediment-associated metals and cyanobacteria by ebullition in a stratified lake"
No full textThe purpose of this collection is to make available to the public the material necessary to validate the research findings for the article listed in "Related Publications." Bubbles adsorb and transport particulate matter both in industrial and marine systems. While methane-containing bubbles emitted from anoxic sediments are found extensively in aquatic ecosystems, relatively little attention has been paid to the possibility that such bubbles transport particle-associated chemical or biological material from sediments to surface waters of freshwater lakes. We quantified transport of particulate material from sediments to the surface by bubbles in Upper Mystic Lake, MA and in a 15 m tall experimental column. Vertical particle transport was positively correlated with the volume of gas bubbles released from the sediment. Particles transported by bubbles originated almost entirely in the sediment, rather than being scavenged from the water column. Concentrations of arsenic, chromium, lead, and cyanobacterial cells in bubble-transported particulate material were similar to those of bulk sediment, and particles were transported from depths exceeding 15 m, resulting in daily fluxes as large as 0.18 µg of arsenic m-2 and 2 x 104 cyanobacterial cells m-2 in the strongly stratified Upper Mystic Lake. While bubble-facilitated arsenic transport currently appears to be a modest component of total arsenic cycling in this lake, bubble-facilitated cyanobacterial transport could comprise as much as 17% of recruitment in this lake and may thus be of particular importance in large, deep, stratified lakes
The Policy and Science for Health, Agriculture and Nutrition (PoSHAN) Seasonal Survey Datasets 2013-2015
No full textThe Feed the Future Innovation Lab for Nutrition, with funding from the USAID, conducted a series of four annual surveys – The Policy and Science for Health, Agriculture and Nutrition (PoSHAN) Surveys – in Nepal from 2013-2015. The aim of the surveys was to assess nutritional status, diet and morbidity of preschool aged children and their mothers, and recently married, nulliparous women, and household food security, agricultural practices, participation in services and programs, among other factors, and examine associations between agricultural practices and food security, nutritional status, diet and health. The broader goal was guide policy and program interventions that may influence household food security, poverty, and the diets, health and nutrition of pre-school children and their mothers.
The PoSHAN surveys were conducted in 21 sub-district units (Village Development Committees, VDCs), in 21 districts, 7 each across the Mountains, Hills and Terai (plains), sampled systematically following a random start. Within each VDC, 3 of 9 wards were systematically sampled, proportional to population size, for a total of 63 wards in the full sample. The PoSHAN surveys were conducted in the same season (~June-August) and wards every year. In addition, 1 VDC, representing an average of the 7 VDCs per zone was surveyed in two additional seasons al (sentinel) surveys to provide year-round agricultural, food security, dietary, nutritional status and other data. The first three were nationally representative (2013, 2014 and 2016) and one was conducted only in the Terai (2015) due to the 2015 Nepal earthquake which mainly affected the Hills and Mountains.
This collection contains the cross-sectional dataset for the seasonal surveys conducted from 2013 through 2015. For more information visit:https://doi.org/10.12691/jfs-6-2-5.
(Link to Annual Surveys.)
Data files are formatted for STATA, and include MS Excel and CSV formats. Data specificity is limited to the regional district level to maintain participants' anonymity for public access. Restricted access to data at the VDC level may be requested by contacting the study team. Additional content details are available in the file set Metadata folder