90 research outputs found
Thanatomicrobiome composition profiling as a tool for forensic investigation.
Thanatomicrobiome, or the postmortem microbiome, has been recognized as a useful microbial marker of the time and location of host death. In this mini-review, we compare the experimental methods commonly applied to thanatomicrobiome studies to the state-of-the-art methodologies in the microbiome field. Then, we review present findings in thanatomicrobiome studies, focusing on the diversity of the thanatomicrobiome composition and prediction models that have been proposed. Finally, we discuss potential improvements and future directions of the field
High-Dose siRNAs Upregulate Mouse Eri-1 at both Transcription and Posttranscription Levels
The eri-1 gene encodes a 3′ exonuclease that can negatively regulate RNA interference via siRNase activity. High-dose siRNAs (hd-siRNAs) can enhance Eri-1 expression, which in return degrade siRNAs and greatly reduces RNAi efficiency. Here we report that hd-siRNAs induce mouse Eri-1 (meri-1) expression through the recruitment of Sp1, Ets-1, and STAT3 to the meri-1 promoter and the formation of an Sp1-Ets-1-STAT3 complex. In addition, hd-siRNAs also abolish the 3′ untranslated region (UTR) mediated posttranscriptional repression of meri-1. Our findings demonstrate the molecular mechanism underlying the upregulation of meri-1 by hd-siRNA
Vitamin E biofortification: enhancement of seed tocopherol concentrations by altered chlorophyll metabolism
Homogentisate Phytyltransferase (HPT) catalyzes condensation of homogentisate (HGA) and phytyl diphosphate (PDP) to produce tocopherols, but can also synthesize tocotrienols using geranylgeranyl diphosphate (GGDP) in plants engineered for deregulated HGA synthesis. In contrast to prior tocotrienol biofortification efforts, engineering enhanced tocopherol concentrations in green oilseeds has proven more challenging due to the integral role of chlorophyll metabolism in supplying the PDP substrate. This study show that RNAi suppression of CHLSYN coupled with HPT overexpression increases tocopherol concentrations by \u3etwo-fold in Arabidopsis seeds. We obtained additional increases in seed tocopherol concentrations by engineering increased HGA production via overexpression of bacterial TyrA that encodes chorismate mutase/prephenate dehydrogenase activities. In overexpression lines, seed tocopherol concentrations increased nearly three-fold, and resulted in modest tocotrienol accumulation. We further increased total tocochromanol concentrations by enhancing production of HGA and GGDP by overexpression of the gene for hydroxyphenylpyruvate dioxygenase (HPPD). This shifted metabolism towards increased amounts of tocotrienols relative to tocopherols, which was reflected in corresponding increases in ratios of GGDP/PDP in these seeds. Overall, our results provide a theoretical basis for genetic improvement of total tocopherol concentrations in green oilseeds (e.g., rapeseed, soybean) through strategies that include seed-suppression of CHLSYN coupled with increased HGA production
Cardiac CT perfusion imaging of pericoronary adipose tissue (PCAT) highlights potential confounds in coronary CTA
Features of pericoronary adipose tissue (PCAT) assessed from coronary
computed tomography angiography (CCTA) are associated with inflammation and
cardiovascular risk. As PCAT is vascularly connected with coronary vasculature,
the presence of iodine is a potential confounding factor on PCAT HU and
textures that has not been adequately investigated. Use dynamic cardiac CT
perfusion (CCTP) to inform contrast determinants of PCAT assessment. From CCTP,
we analyzed HU dynamics of territory-specific PCAT, myocardium, and other
adipose depots in patients with coronary artery disease. HU, blood flow, and
radiomics were assessed over time. Changes from peak aorta time, Pa, chosen to
model the time of CCTA, were obtained. HU in PCAT increased more than in other
adipose depots. The estimated blood flow in PCAT was ~23% of that in the
contiguous myocardium. Comparing PCAT distal and proximal to a significant
stenosis, we found less enhancement and longer time-to-peak distally.
Two-second offsets [before, after] Pa resulted in [ 4-HU, 3-HU] differences in
PCAT. Due to changes in HU, the apparent PCAT volume reduced ~15% from the
first scan (P1) to Pa using a conventional fat window. Comparing radiomic
features over time, 78% of features changed >10% relative to P1. CCTP
elucidates blood flow in PCAT and enables analysis of PCAT features over time.
PCAT assessments (HU, apparent volume, and radiomics) are sensitive to
acquisition timing and the presence of obstructive stenosis, which may confound
the interpretation of PCAT in CCTA images. Data normalization may be in order.Comment: 13 pages, 8 figure
Coronary CTA and Quantitative Cardiac CT Perfusion (CCTP) in Coronary Artery Disease
We assessed the benefit of combining stress cardiac CT perfusion (CCTP)
myocardial blood flow (MBF) with coronary CT angiography (CCTA) using our
innovative CCTP software. By combining CCTA and CCTP, one can uniquely identify
a flow limiting stenosis (obstructive-lesion + low-MBF) versus MVD
(no-obstructive-lesion + low-MBF. We retrospectively evaluated 104 patients
with suspected CAD, including 18 with diabetes, who underwent CCTA+CCTP. Whole
heart and territorial MBF was assessed using our automated pipeline for CCTP
analysis that included beam hardening correction; temporal scan registration;
automated segmentation; fast, accurate, robust MBF estimation; and
visualization. Stenosis severity was scored using the CCTA
coronary-artery-disease-reporting-and-data-system (CAD-RADS), with obstructive
stenosis deemed as CAD-RADS>=3. We established a threshold MBF
(MBF=199-mL/min-100g) for normal perfusion. In patients with CAD-RADS>=3,
28/37(76%) patients showed ischemia in the corresponding territory. Two
patients with obstructive disease had normal perfusion, suggesting collaterals
and/or a hemodynamically insignificant stenosis. Among diabetics, 10 of 18
(56%) demonstrated diffuse ischemia consistent with MVD. Among non-diabetics,
only 6% had MVD. Sex-specific prevalence of MVD was 21%/24% (M/F). On a
per-vessel basis (n=256), MBF showed a significant difference between
territories with and without obstructive stenosis (165 +/- 61 mL/min-100g vs.
274 +/- 62 mL/min-100g, p <0.05). A significant and negative rank correlation
(rho=-0.53, p<0.05) between territory MBF and CAD-RADS was seen. CCTA in
conjunction with a new automated quantitative CCTP approach can augment the
interpretation of CAD, enabling the distinction of ischemia due to obstructive
lesions and MVD
Decentralized Agent Based Re-Clustering for Task Mapping of Tera-Scale Network-on-Chip System
With the rapid increasing demand for high-performance computing, such as cloud computing, Tera (flops) scale high-performance computing system composed of hundreds of on-chip processing cores has become the recent interest. Given a large-scale computing system such as network-on-chip (NoC) with hundreds of cores, bandwidth and power density are the fundamental limits dominated by on-chip communication. This has brought extreme challenge when mapping application tasks onto Tera-scale NoC system. Previous task mapping scheme is mainly centralized and static, and hence results in large communication volume, not scalable for runtime task mapping required by Tera-scale NoC system. In order to improve on-chip traffic and reduce power density for the need of Tera-scale NoC system, we have proposed a de-centralized re-clustering algorithm. The processing cores in the NoC system are organized into clusters with an efficient decentralized re-clustering scheme to adjust the cluster size for the task mapping. As such, the communication volume can be significantly reduced and result in decreased power. Experimental results have demonstrated that our proposed algorithm can achieve reduction of communication traffic (up to 66.7%). The energy consumption profile has also been efficiently improved to reduce the hotspots
A Variation-Aware Adaptive Fuzzy Control System for Thermal Management of Microprocessors
Thermal failures pose severe threats to reliability and performance of modern microprocessors, which calls for thermal management solutions to effectively control the temperature within a processor. Among various thermal management techniques, closed-loop thermal controllers have the advantages of high control accuracy and high response speed. However, it is challenging for closed-loop thermal controllers to deal with static and dynamic thermal model uncertainties, which significantly affect the control quality of the controller. In this paper, we propose an adaptive fuzzy controller for thermal management of microprocessors with adaptability to thermal model variations. The experiments with microbenchmarks and the SPEC CPU2006 benchmarks demonstrate that our adaptive fuzzy controller maintains the control quality when faced with severe variations of the thermal model. Compared with state-of-the-art thermal controllers with thermal model calibration capabilities, our design shows a comparable performance with much lower complexity and design cost.Accepted versio
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