2,688 research outputs found
A Meta-Narrative Review on the Use of R.O.S.E in Telecytology for the Patient, Pathologist, and Cytologist
Advancements in technology have given rise to a path of convenience, ease, and flexibility for workers to work remotely. A new tool in laboratory diagnostics is Telecytology for Rapid On-Site Evaluation. A cytologist processes a specimen on site and captures an image or video of the findings. The media is sent directly to a pathologist for further evaluation, and then a diagnosis is given to the patient. With this being a relatively new practice, we need to ask what the advantages and disadvantages are for everyone involved: the patient, the cytologist, and the pathologist. We found articles that were less than five years old and reviewed the methodologies in the articles. We found that there were many advantages including decreased diagnosis time, availability to patients in rural areas, and fewer repeated procedures. We also found disadvantages such as extensive training requirements and the possibility of incorrect diagnoses. Our findings indicate there is success in using Telecytology for R.O.S.E., but that faults are present to some degree. As technology continues to advance, we expect more studies to be conducted that highlight the success of Teleyctology with Rapid On-Site Evaluation.https://openworks.mdanderson.org/rmps/1007/thumbnail.jp
Gemini-South + FLAMINGOS Demonstration Science: Near-Infrared Spectroscopy of the z=5.77 Quasar SDSS J083643.85+005453.3
We report an infrared 1-1.8 micron (J+H-bands), low-resolution (R=450)
spectrogram of the highest-redshift radio-loud quasar currently known, SDSS
J083643.85+005453.3, obtained during the spectroscopic commissioning run of the
FLAMINGOS multi-object, near-infrared spectrograph at the 8m Gemini-South
Observatory. These data show broad emission from both CIV 1549 and CIII] 1909,
with strengths comparable to lower-redshift quasar composite spectra. The
implication is that there is substantial enrichment of the quasar environment,
even at times less than a billion years after the Big Bang. The redshift
derived from these features is z = 5.774 +/- 0.003, more accurate and slightly
lower than the z = 5.82 reported in the discovery paper based on the
partially-absorbed Lyman-alpha emission line. The infrared continuum is
significantly redder than lower-redshift quasar composites. Fitting the
spectrum from 1.0 to 1.7 microns with a power law f(nu) ~ nu^(-alpha), the
derived power law index is alpha = 1.55 compared to the average continuum
spectral index = 0.44 derived from the first SDSS composite quasar.
Assuming an SMC-like extinction curve, we infer a color excess of E(B-V) = 0.09
+/- 0.01 at the quasar redshift. Only approximately 6% of quasars in the
optically-selected Sloan Digital Sky Survey show comparable levels of dust
reddening.Comment: 10 pages, 1 figure; to appear in the Astrophysical Journal Letter
3-D Finite Di erence Modeling for Borehole and Reservoir Applications
ERL's in-house nite difference code (Krasovec et al., 2003) has undergone several upgrades in the past year. Most notably, a stretched grid can now be used to greatly reduce the amount of RAM memory needed by certain types of models. Improvements have been made in the GUI front end, allowing more freedom and ease in building the model, source or source array, and receiver array.
The finite difference code has contributed to several different research projects at ERL in the past year. A few of these projects, including borehole seismics, reservoir delineation, and source mechanics, are shown in this report.Massachusetts Institute of Technology. Earth Resources LaboratoryMassachusetts Institute of Technology. Borehole Acoustics and Logging Consortiu
Fracture Detection using Amplitude versus Offset and Azimuth Analysis of a 3D P-wave Seismic Dataset and Synthetic Examples
Amplitude versus offset (AVO) analysis of seismic reflection data has been a successful tool in describing changes in rock properties along a reflector. This method is extended to azimuthal AVO (AVOA) in order to characterize vertically aligned fractures within a reservoir, which can be important fluid migration pathways. AVOA analysis is performed on synthetic data using a least squares inversion method to investigate the effects of varying acquisition geometry, amount of noise, and fracture properties. These tests show that it is possible to detect the fractured layer and determine the fracture strike orientation under typical acquisition conditions. This method is also applied to field data collected during an Ocean Bottom Cable (OBC) survey. These data include a broad offset-azimuth range, which is important for the AVOA analysis. The fracture location and strike orientation recovered from the field data analysis are well correlated with borehole information from this area. Based on an understanding of AVOA behavior under synthetic conditions, this technique provides an effective methodology for describing the spatial variability of a fractured reservoir using 3D seismic data.Eni S.p.A. (Firm)United States. Dept. of Energy (Grant number DE-FC26-02NT15346)Massachusetts Institute of Technology. Earth Resources Laborator
Dynamics and Instabilities of Planar Tensile Cracks in Heterogeneous Media
The dynamics of tensile crack fronts restricted to advance in a plane are
studied. In an ideal linear elastic medium, a propagating mode along the crack
front with a velocity slightly less than the Rayleigh wave velocity, is found
to exist. But the dependence of the effective fracture toughness on
the crack velocity is shown to destabilize the crack front if
. Short wavelength radiation due to weak random
heterogeneities leads to this instability at low velocities. The implications
of these results for the crack dynamics are discussed.Comment: 12 page
Treating Early-Stage CKD With New Medication Therapies:Results of a CKD Patient Survey Informing the 2020 NKF-FDA Scientific Workshop on Clinical Trial Considerations for Developing Treatments for Early Stages of Common, Chronic Kidney Diseases
RATIONALE & OBJECTIVE: With a growing number of medications and therapies available to treat chronic kidney disease (CKD), risk-versus-benefit discussions are increasingly critical. Balancing risks and benefits requires assessing patients’ understanding of these, as well as incorporating patient preferences and tolerance for side effects into shared decision making. STUDY DESIGN: A 26-question online survey was sent to people in the National Kidney Foundation patient email list and posted on associated social media pages to assess the respondents’ willingness and comfort with taking preventative medications during earlier-stage CKD to inform a December 2020 scientific workshop co-sponsored by the National Kidney Foundation and the US Food and Drug Administration on clinical trial considerations in developing treatments for individuals with early stages of CKD. SETTING & POPULATION: Online survey of CKD patients, including broad demographic data and responses to risk-benefit scenarios, with surveys emailed to 20,249 people not identified as currently receiving kidney replacement therapy. ANALYTICAL APPROACH: Survey results are presented as descriptive data. RESULTS: Of 1,029 respondents, 45 self-identified as at risk for CKD, 566 had CKD, 267 had received kidney transplants, 51 were receiving dialysis, and 100 replied other or did not answer. Respondents reported being willing to assume some risk with the goal of preventing the progression of CKD, with a greater willingness to assume risk and treatment burdens the closer they came to late-stage disease. Clinician recommendations regarding kidney therapies and clinician willingness to work with patients to address any side effects were important in respondents’ willingness to initiate and persevere with a new medication. LIMITATIONS: Approximately 10% response rate with limited data on respondents. CONCLUSIONS: Risk-versus-benefit discussions appear key to patients and their care partners making well-informed decisions about taking a new medication that may or may not help the progression of their kidney disease. Future tools and strategies are needed to facilitate informed discussions of treatment in early-stage kidney disease
The Multiwavelength Survey by Yale-Chile (MUSYC): Deep Near-Infrared Imaging and the Selection of Distant Galaxies
We present deep near-infrared JHK imaging of four 10'x10' fields. The
observations were carried out as part of the Multiwavelength Survey by
Yale-Chile (MUSYC) with ISPI on the CTIO 4m telescope. The typical point source
limiting depths are J~22.5, H~21.5, and K~21 (5sigma; Vega). The effective
seeing in the final images is ~1.0". We combine these data with MUSYC UBVRIz
imaging to create K-selected catalogs that are unique for their uniform size,
depth, filter coverage, and image quality. We investigate the rest-frame
optical colors and photometric redshifts of galaxies that are selected using
common color selection techniques, including distant red galaxies (DRGs),
star-forming and passive BzKs, and the rest-frame UV-selected BM, BX, and Lyman
break galaxies (LBGs). These techniques are effective at isolating large
samples of high redshift galaxies, but none provide complete or uniform samples
across the targeted redshift ranges. The DRG and BM/BX/LBG criteria identify
populations of red and blue galaxies, respectively, as they were designed to
do. The star-forming BzKs have a very wide redshift distribution, a wide range
of colors, and may include galaxies with very low specific star formation
rates. In comparison, the passive BzKs are fewer in number, have a different
distribution of K magnitudes, and have a somewhat different redshift
distribution. By combining these color selection criteria, it appears possible
to define a reasonably complete sample of galaxies to our flux limit over
specific redshift ranges. However, the redshift dependence of both the
completeness and sampled range of rest-frame colors poses an ultimate limit to
the usefulness of these techniques.Comment: 17 pages in emulateapj style, 13 figures. Submitted to the
Astronomical Journal. Data will be made available upon publicatio
Onset of Propagation of Planar Cracks in Heterogeneous Media
The dynamics of planar crack fronts in hetergeneous media near the critical
load for onset of crack motion are investigated both analytically and by
numerical simulations. Elasticity of the solid leads to long range stress
transfer along the crack front which is non-monotonic in time due to the
elastic waves in the medium. In the quasistatic limit with instantaneous stress
transfer, the crack front exhibits dynamic critical phenomenon, with a second
order like transition from a pinned to a moving phase as the applied load is
increased through a critical value. At criticality, the crack-front is
self-affine, with a roughness exponent . The dynamic
exponent is found to be equal to and the correlation length
exponent . These results are in good agreement with those
obtained from an epsilon expansion. Sound-travel time delays in the stress
transfer do not change the static exponents but the dynamic exponent
becomes exactly one. Real elastic waves, however, lead to overshoots in the
stresses above their eventual static value when one part of the crack front
moves forward. Simplified models of these stress overshoots are used to show
that overshoots are relevant at the depinning transition leading to a decrease
in the critical load and an apparent jump in the velocity of the crack front
directly to a non-zero value. In finite systems, the velocity also shows
hysteretic behaviour as a function of the loading. These results suggest a
first order like transition. Possible implications for real tensile cracks are
discussed.Comment: 51 pages + 20 figur
Scabies prevalence after ivermectin-based mass drug administration for lymphatic filariasis, Samoa 2018–2019
Background: Scabies is a common skin infestation caused by the Sarcoptes scabei mite. Ivermectin, one of three drugs used in mass drug administration (MDA) for lymphatic filariasis, is also effec-tive for treating scabies. Ivermectin-based MDA was first conducted in Samoa in August 2018, with ivermectin being offered to those aged ≥5 years. Here, we report scabies prevalence in Samoa after MDA.
Methods: We conducted household surveys 1.5–3.5 months (Survey 1) and 6–8 months (Survey 2) after the 2018 MDA in 35 primary sampling units. We conducted clinical examination for sca-bies-like rash and used International Alliance for the Control of Scabies classification crite-ria. We estimated scabies prevalence by age, gender and region. Multivariable logistic regression was used to assess factors associated with prevalence.
Results: We surveyed 2868 people (499 households) and 2796 people (544 households) aged 0–75 years in Surveys 1 and 2, respectively. Scabies prevalence increased from 2.4% (95% CI 2.1–2.7%) to 4.4% (95% CI 4.0–4.9%) between surveys. Scabies was associated with younger age (0–4 years: aOR 3.5 [2.9–4.2]; 5–15 years: aOR 1.6 [1.4–1.8] compared to ≥16 years), female gender (aOR 1.2 [95% CI 1.1–1.4]; region (aOR range from 1.4 [1.1– 1.7] to 2.5 [2.1–3.1] between regions), large households (aOR 2.6 [2.0–3.4] households ≥13), and not taking MDA in 2018 (aOR 1.3 [95% CI 1.1–1.6]).
Conclusions: We found moderate prevalence of scabies in two population-representative surveys conducted within 8 months of the 2018 MDA for lymphatic filariasis. Prevalence appeared to increase between the surveys, and ongoing surveillance is recommended, particularly in young children
Evaluating predictive pharmacogenetic signatures of adverse events in colorectal cancer patients treated with fluoropyrimidines
The potential clinical utility of genetic markers associated with response to fluoropyrimidine treatment in colorectal cancer patients remains controversial despite extensive study. Our aim was to test the clinical validity of both novel and previously identified markers of adverse events in a broad clinical setting. We have conducted an observational pharmacogenetic study of early adverse events in a cohort study of 254 colorectal cancer patients treated with 5-fluorouracil or capecitabine. Sixteen variants of nine key folate (pharmacodynamic) and drug metabolising (pharmacokinetic) enzymes have been analysed as individual markers and/or signatures of markers. We found a significant association between TYMP S471L (rs11479) and early dose modifications and/or severe adverse events (adjusted OR = 2.02 [1.03; 4.00], p = 0.042, adjusted OR = 2.70 [1.23; 5.92], p = 0.01 respectively). There was also a significant association between these phenotypes and a signature of DPYD mutations (Adjusted OR = 3.96 [1.17; 13.33], p = 0.03, adjusted OR = 6.76 [1.99; 22.96], p = 0.002 respectively). We did not identify any significant associations between the individual candidate pharmacodynamic markers and toxicity. If a predictive test for early adverse events analysed the TYMP and DPYD variants as a signature, the sensitivity would be 45.5 %, with a positive predictive value of just 33.9 % and thus poor clinical validity. Most studies to date have been under-powered to consider multiple pharmacokinetic and pharmacodynamic variants simultaneously but this and similar individualised data sets could be pooled in meta-analyses to resolve uncertainties about the potential clinical utility of these markers
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