431 research outputs found
The Secrets of Non-Blind Poisson Deconvolution
Non-blind image deconvolution has been studied for several decades but most
of the existing work focuses on blur instead of noise. In photon-limited
conditions, however, the excessive amount of shot noise makes traditional
deconvolution algorithms fail. In searching for reasons why these methods fail,
we present a systematic analysis of the Poisson non-blind deconvolution
algorithms reported in the literature, covering both classical and deep
learning methods. We compile a list of five "secrets" highlighting the do's and
don'ts when designing algorithms. Based on this analysis, we build a
proof-of-concept method by combining the five secrets. We find that the new
method performs on par with some of the latest methods while outperforming some
older ones.Comment: Under submission at Transactions on Computational Imagin
Kernel Diffusion: An Alternate Approach to Blind Deconvolution
Blind deconvolution problems are severely ill-posed because neither the
underlying signal nor the forward operator are not known exactly.
Conventionally, these problems are solved by alternating between estimation of
the image and kernel while keeping the other fixed. In this paper, we show that
this framework is flawed because of its tendency to get trapped in local minima
and, instead, suggest the use of a kernel estimation strategy with a non-blind
solver. This framework is employed by a diffusion method which is trained to
sample the blur kernel from the conditional distribution with guidance from a
pre-trained non-blind solver. The proposed diffusion method leads to
state-of-the-art results on both synthetic and real blur datasets
Structured Kernel Estimation for Photon-Limited Deconvolution
Images taken in a low light condition with the presence of camera shake
suffer from motion blur and photon shot noise. While state-of-the-art image
restoration networks show promising results, they are largely limited to
well-illuminated scenes and their performance drops significantly when photon
shot noise is strong.
In this paper, we propose a new blur estimation technique customized for
photon-limited conditions. The proposed method employs a gradient-based
backpropagation method to estimate the blur kernel. By modeling the blur kernel
using a low-dimensional representation with the key points on the motion
trajectory, we significantly reduce the search space and improve the regularity
of the kernel estimation problem. When plugged into an iterative framework, our
novel low-dimensional representation provides improved kernel estimates and
hence significantly better deconvolution performance when compared to
end-to-end trained neural networks. The source code and pretrained models are
available at \url{https://github.com/sanghviyashiitb/structured-kernel-cvpr23}Comment: main document and supplementary; accepted at CVPR202
Abbott's fluorescence polarization immunoassay for cyclosporine and metabolites compared with the Sandoz "Sandimmune" RIA
A new procedure for measuring cyclosporine in plasma has been introduced by Abbott Laboratories, involving their TDx instrumentation and fluorescence polarization immunoassay. Radioimmunoassay (RIA) and high-performance liquid chromatography are currently the conventional methods for measuring cyclosporine in plasma and whole blood. In an effort to find a method that will decrease the radioactive hazard, the reagent and supply cost, and the labor requirements associated with RIA procedures, we used specimens from transplantation patients to compare the Abbott assay with the Sandoz Sandimmune assay. We believe that the Abbott assay offers some advantages over the Sandimmune RIA procedure, providing a reliable but simpler and less hazardous technology
Helping rural women in Pakistan to prevent postpartum hemorrhage: A quasi experimental study
BACKGROUND: According to the Pakistan Demographic and Health Survey from 2006–2007, the maternal mortality ratio in rural areas is 319 per 100,000 live births. Postpartum hemorrhage is the leading cause of maternal deaths in Pakistan. The objectives of the study were to document the feasibility of distribution of misoprostol tablets by community-based providers mainly traditional birth attendants and acceptability and use of misoprostol by women who gave birth at home. METHODS: A quasi-experimental design, comprising intervention and comparison areas, was used to document the acceptability of providing misoprostol tablets to pregnant women to prevent postpartum hemorrhage in the rural community setting in Pakistan. Data were collected using structured questionnaires administered to women before and after delivery at home and their birth attendants. RESULTS: Out of 770 women who delivered at home, 678 (88%) ingested misoprostol tablets and 647 (84%) ingested the tablets after the birth of the neonate but prior to the delivery of the placenta. The remaining women took misoprostol tablets after delivery of the placenta. Side effects were experienced by 40% of women and were transitory in nature. Among women who delivered at home, 80% said that they would use misoprostol tablets in the future and 74% were willing to purchase them in the future. CONCLUSIONS: Self-administration of misoprostol in the home setting is feasible. Community-based providers, such as traditional birth attendants and community midwives with proper training and counseling, play an important role in reducing postpartum hemorrhage. Proper counseling and information exchange are helpful for introducing new practices in resource-constrained rural communities. Until such a time that skilled birth attendance is made more universally available in the rural setting, alternative strategies, such as training and using the services of traditional birth attendants to provide safe pregnancy care, must be considered
Cyclosporine metabolism and pharmaco-kinetics following intravenous and oral doses in the dog
Comprehensive serial molecular profiling of an “N of 1” exceptional non-responder with metastatic prostate cancer progressing to small cell carcinoma on treatment
Abstract
Importance
Small cell carcinoma/neuroendocrine prostate cancer (NePC) is a lethal, poorly understood prostate cancer (PCa) subtype. Controversy exists about the origin of NePC in this setting.
Objective
To molecularly profile archived biopsy specimens from a case of early-onset PCa that rapidly progressed to NePC to identify drivers of the aggressive course and mechanisms of NePC origin and progression.
Design, setting, and participants
A 47-year-old patient presented with metastatic prostatic adenocarcinoma (Gleason score 9). After a 6-month response to androgen deprivation therapy, the patient developed jaundice and liver biopsy revealed exclusively NePC. Targeted next generation sequencing (NGS) from formalin-fixed paraffin-embedded (FFPE)-isolated DNA was performed from the diagnostic prostate biopsy and the liver biopsy at progression.
Intervention
Androgen deprivation therapy for adenocarcinoma followed by multiagent chemotherapy for NePC.
Main outcomes and measures
Identification of the mutational landscape in primary adenocarcinoma and NePC liver metastasis. Whether the NePC arose independently or was derived from the primary adenocarcinoma was considered based on mutational profiles.
Results
A deleterious somatic SMAD4 L535fs variant was present in both prostate and liver specimens; however, a TP53 R282W mutation was exclusively enriched in the liver specimen. Copy number analysis identified concordant, low-level alterations in both specimens, with focal MYCL amplification and homozygous PTEN, RB1, and MAP2K4 losses identified exclusively in the NePC specimen. Integration with published genomic profiles identified MYCL as a recurrently amplified in NePC.
Conclusions and relevance
NGS of routine biopsy samples from an exceptional non-responder identified SMAD4 as a driver of the aggressive course and supports derivation of NePC from primary adenocarcinoma (transdifferentiation).http://deepblue.lib.umich.edu/bitstream/2027.42/113670/1/13045_2015_Article_204.pd
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