143 research outputs found
Mucinous neoplasia of appendix: imaging and its relevance to management
Appendiceal mucocele is a rare pathology of the appendix that can present with non-specific symptoms. Therefore, imaging evaluation is essential for accurate diagnosis and proper management. To document importance of pre-operative imaging, we reviewed the scans, reports, and clinical data of nine patients with appendiceal mucocele who were treated at our institute. We also studied the literature on CT findings, histopathology, surgical management, prognosis, and recent guidelines for appendiceal mucocele. We suggest that pre-operative imaging can aid surgeons in selecting the most appropriate treatment plan for each patient, resulting in better outcomes. Certain critical imaging features, such as mural nodularity, irregular wall thickening, lymphadenopathy, cecal involvement, presence of free mucus, or pseudomyxoma peritonei, can alert surgeons to prepare for frozen section and an appropriate surgical approach. In conclusion, we recommend pre-operative imaging as a crucial tool for the diagnosis and management of appendiceal mucocele. Its use in identifying critical imaging features can help surgeons decide on the best surgical approach for each patient and ultimately lead to better outcomes
Mechanistic modeling of pollutant removal, temperature, and evaporation in chemical air scrubbers
Chemical air scrubbers reduce the concentration of water-soluble components such as ammonia from the outgoing ventilation air through absorption in water, followed by chemical conversions and removal of the end products. A mechanistic model for a countercurrent air scrubber was set up. Mass balances for ammonia, hydrogen sulfide, nitrous oxide, and methane were implemented, as well as the water mass balance and heat balances. The model was validated against experimental data from a conventional fattening pig housing facility. The effect of influent characteristics, design parameters, and control handles on the removal efficiency, the temperature profile, and the water evaporation rate were investigated through simulation. The model was able to describe the behavior of a countercurrent chemical air scrubber
Reliability of an automatic classifier for brain enlarged perivascular spaces burden and comparison with human performance
In the brain, enlarged perivascular spaces (PVS) relate to cerebral small vessel disease (SVD),
poor cognition, inflammation and hypertension. We propose a fully automatic scheme that
uses a support vector machine (SVM) to classify the burden of PVS in the basal ganglia
(BG) region as low or high. We assess the performance of three different types of descriptors
extracted from the BG region in T2-weighted MRI images: (i) statistics obtained
from Wavelet transformâs coefficients, (ii) local binary patterns and (iii) bag of visual words
(BoW) based descriptors characterizing local keypoints obtained from a dense grid with the
scale-invariant feature transform (SIFT) characteristics. When the latter were used, the SVM
classifier achieved the best accuracy (81.16%). The output from the classifier using the BoW
descriptors was compared with visual ratings done by an experienced neuroradiologist (Observer
1) and by a trained image analyst (Observer 2). The agreement and cross-correlation
between the classifier and Observer 2 (Îș = 0.67 (0.58â0.76)) were slightly higher than between
the classifier and Observer 1 (Îș = 0.62 (0.53â0.72)) and comparable between both
the observers (Îș = 0.68 (0.61â0.75)). Finally, three logistic regression models using clinical
variables as independent variable and each of the PVS ratings as dependent variable
were built to assess how clinically meaningful were the predictions of the classifier. The
goodness-of-fit of the model for the classifier was good (area under the curve (AUC) values:
0.93 (model 1), 0.90 (model 2) and 0.92 (model 3)) and slightly better (i.e. AUC values: 0.02
units higher) than that of the model for Observer 2. These results suggest that, although it
can be improved, an automatic classifier to assess PVS burden from brain MRI can provide
clinically meaningful results close to those from a trained observer
Emissions and Energy Impacts of the Inflation Reduction Act
If goals set under the Paris Agreement are met, the world may hold warming
well below 2 C; however, parties are not on track to deliver these commitments,
increasing focus on policy implementation to close the gap between ambition and
action. Recently, the US government passed its most prominent piece of climate
legislation to date, the Inflation Reduction Act of 2022 (IRA), designed to
invest in a wide range of programs that, among other provisions, incentivize
clean energy and carbon management, encourage electrification and efficiency
measures, reduce methane emissions, promote domestic supply chains, and address
environmental justice concerns. IRA's scope and complexity make modeling
important to understand impacts on emissions and energy systems. We leverage
results from nine independent, state-of-the-art models to examine potential
implications of key IRA provisions, showing economy wide emissions reductions
between 43-48% below 2005 by 2035
The Transcriptome of the Intraerythrocytic Developmental Cycle of Plasmodium falciparum
Plasmodium falciparum is the causative agent of the most burdensome form of human malaria, affecting 200â300 million individuals per year worldwide. The recently sequenced genome of P. falciparum revealed over 5,400 genes, of which 60% encode proteins of unknown function. Insights into the biochemical function and regulation of these genes will provide the foundation for future drug and vaccine development efforts toward eradication of this disease. By analyzing the complete asexual intraerythrocytic developmental cycle (IDC) transcriptome of the HB3 strain of P. falciparum, we demonstrate that at least 60% of the genome is transcriptionally active during this stage. Our data demonstrate that this parasite has evolved an extremely specialized mode of transcriptional regulation that produces a continuous cascade of gene expression, beginning with genes corresponding to general cellular processes, such as protein synthesis, and ending with Plasmodium-specific functionalities, such as genes involved in erythrocyte invasion. The data reveal that genes contiguous along the chromosomes are rarely coregulated, while transcription from the plastid genome is highly coregulated and likely polycistronic. Comparative genomic hybridization between HB3 and the reference genome strain (3D7) was used to distinguish between genes not expressed during the IDC and genes not detected because of possible sequence variations. Genomic differences between these strains were found almost exclusively in the highly antigenic subtelomeric regions of chromosomes. The simple cascade of gene regulation that directs the asexual development of P. falciparum is unprecedented in eukaryotic biology. The transcriptome of the IDC resembles a âjust-in-timeâ manufacturing process whereby induction of any given gene occurs once per cycle and only at a time when it is required. These data provide to our knowledge the first comprehensive view of the timing of transcription throughout the intraerythrocytic development of P. falciparum and provide a resource for the identification of new chemotherapeutic and vaccine candidates
Mechanistic Modeling of Pollutant Removal, Temperature, and Evaporation in Chemical Air Scrubbers
An experimental and computational study of the aerodynamic and passive ventilation characteristics of small livestock trailers
This paper presents a combined experimental and computational study of the aerodynamics and passive ventilation characteristics of small livestock trailers within which the majority of animals in the United Kingdom are transported to market. Data obtained from a series of wind tunnel experiments using a 1/7th scale model of a simplified towing vehicle and trailer is compared with complementary Computational Fluid Dynamics (CFD) analyses, based on steady-state RANS turbulence modelling, of the coupled external/internal flow field. Good agreement between the two is obtained everywhere except at the rear of the trailer. Since the internal flow field and overall ventilation rates contribute to animal welfare, CFD is used to generate detailed internal flow fields and air residence times for use within an overall welfare assessment. The results demonstrate that the flow fields in the upper and lower decks differ significantly and that ventilation rates are much larger and air residence times much smaller on the upper deck
- âŠ