307 research outputs found
Temporal Self-Regulation of Energy Demand
The increase in the deployment of smart meters has enabled collection of fine-grained energy consumption data at consumer premises. Analysis of this real-time energy consumption data bestows new opportunities for better demand-response (DR) programs. This paper offers a new perspective to study energy demand and helps in designing novel mechanisms for decentralized demand-side management. Specifically, a new concept of finding the demand states using energy consumption of consumers over time and feasible transitions therein is introduced. It is shown that the orchestration of temporal transitions between the demand states can meet broad range of smart grid objectives. An online demand regulation model is developed that captures the temporal dynamics of energy demand to identify target consumers for different DR programs. This methodology is empirically evaluated and validated using data from more than 4000 households, which were part of a real-world smart grid project. This paper is the first one to comprehensively analyze the temporal dynamics of demands
Nutritional Evaluation of Banana Peelings from the Various Banana Varieties in Different Regions of Uganda
In Uganda, peri-urban agriculture is very important in sustaining livelihoods of the increasing population in urban and peri-urban (U & PU) areas. However, this form of agriculture has a number of problems, feed shortage being the most important. The agricultural produce brought in from the rural areas is marketed in raw form hence increasing the crop wastes in the market areas. The crop wastes, if properly sorted, can serve as alternative feeds for the animals kept in the U & PU areas. Banana (Musa spp) peelings (BP) constitute the largest proportion of all the crop wastes in most markets in areas where they are the staple food crop and have become a popular feedstuff. Unfortunately, there is scanty literature on their nutritive and feeding value. Different varieties are grown in the different banana growing areas. The purpose of this study was to evaluate the nutritive value of BP of the different banana varieties from central, eastern and western Uganda. In vitro dry matter digestibility (INDMD) of the banana peelings was also determined
ORBIT: a new paradigm for genetic engineering of mycobacterial chromosomes [preprint]
Current methods for genome engineering in mycobacteria rely on relatively inefficient recombination systems that require the laborious construction of a long double-stranded DNA substrate for each desired modification. We combined two efficient recombination systems to produce a versatile method for high-throughput chromosomal engineering that obviates the need for the preparation of double-stranded DNA recombination substrates. A synthetic targeting oligonucleotide is incorporated into the chromosome via homologous recombination mediated by the phage Che9c RecT annelase. This oligo contains a site-specific recombination site for the directional Bxb1 integrase (Int), which allows the simultaneous integration of a payload plasmid that contains a cognate recombination site and selectable marker. The targeting oligo and payload plasmid are co-transformed into a RecT- and Int- expressing strain, and drug-resistant homologous recombinants are selected in a single step. A library of reusable target-independent payload plasmids is available to generate knockouts and promoter replacements, or to fuse the C-terminal-encoding regions of target genes with tags of various functionalities. This new system is called ORBIT (Oligo-mediated Recombineering followed by Bxb1 Integrase Targeting) and is ideally suited for the creation of libraries consisting of large numbers of deletions, insertions or fusions in a target bacterium. We demonstrate the utility of ORBIT by the construction of insertions or deletions in over 100 genes in M. tuberculosis and M. smegmatis. The report describes the first genetic engineering technique for making selectable chromosomal fusions and deletions that does not require the construction of target- or modification-specific double-stranded DNA recombination substrates
Statistical analysis of genetic interactions in Tn-Seq data
Tn-Seq is an experimental method for probing the functions of genes through construction of complex random transposon insertion libraries and quantification of each mutant\u27s abundance using next-generation sequencing. An important emerging application of Tn-Seq is for identifying genetic interactions, which involves comparing Tn mutant libraries generated in different genetic backgrounds (e.g. wild-type strain versus knockout strain). Several analytical methods have been proposed for analyzing Tn-Seq data to identify genetic interactions, including estimating relative fitness ratios and fitting a generalized linear model. However, these have limitations which necessitate an improved approach. We present a hierarchical Bayesian method for identifying genetic interactions through quantifying the statistical significance of changes in enrichment. The analysis involves a four-way comparison of insertion counts across datasets to identify transposon mutants that differentially affect bacterial fitness depending on genetic background. Our approach was applied to Tn-Seq libraries made in isogenic strains of Mycobacterium tuberculosis lacking three different genes of unknown function previously shown to be necessary for optimal fitness during infection. By analyzing the libraries subjected to selection in mice, we were able to distinguish several distinct classes of genetic interactions for each target gene that shed light on their functions and roles during infection
Fine-tuning of Substrate Affinity Leads to Alternative Roles of Mycobacterium tuberculosis Fe2+-ATPases
Little is known about iron efflux transporters within bacterial systems. Recently, the participation of Bacillus subtilis PfeT, a P1B4-ATPase, in cytoplasmic Fe(2+) efflux has been proposed. We report here the distinct roles of mycobacterial P1B4-ATPases in the homeostasis of Co(2+) and Fe(2+) Mutation of Mycobacterium smegmatis ctpJ affects the homeostasis of both ions. Alternatively, an M. tuberculosis ctpJ mutant is more sensitive to Co(2+) than Fe(2+), whereas mutation of the homologous M. tuberculosis ctpD leads to Fe(2+) sensitivity but no alterations in Co(2+) homeostasis. In vitro, the three enzymes are activated by both Fe(2+) and Co(2+) and bind 1 eq of either ion at their transport site. However, equilibrium binding affinities and activity kinetics show that M. tuberculosis CtpD has higher affinity for Fe(2+) and twice the Fe(2+)-stimulated activity than the CtpJs. These parameters are paralleled by a lower activation and affinity for Co(2+) Analysis of Fe(2+) and Co(2+) binding to CtpD by x-ray absorption spectroscopy shows that both ions are five- to six-coordinate, constrained within oxygen/nitrogen environments with similar geometries. Mutagenesis studies suggest the involvement of invariant Ser, His, and Glu residues in metal coordination. Interestingly, replacement of the conserved Cys at the metal binding pocket leads to a large reduction in Fe(2+) but not Co(2+) binding affinity. We propose that CtpJ ATPases participate in the control of steady state Fe(2+) levels. CtpD, required for M. tuberculosis virulence, is a high affinity Fe(2+) transporter involved in the rapid response to iron dyshomeostasis generated upon redox stress
The Oxidative Stress Network of Mycobacterium tuberculosis Reveals Coordination between Radical Detoxification Systems
SummaryM. tuberculosis (Mtb) survives a hostile environment within the host that is shaped in part by oxidative stress. The mechanisms used by Mtb to resist these stresses remain ill-defined because the complex combination of oxidants generated by host immunity is difficult to accurately recapitulate in vitro. We performed a genome-wide genetic interaction screen to comprehensively delineate oxidative stress resistance pathways necessary for Mtb to resist oxidation during infection. Our analysis predicted functional relationships between the superoxide-detoxifying enzyme (SodA), an integral membrane protein (DoxX), and a predicted thiol-oxidoreductase (SseA). Consistent with that, SodA, DoxX, and SseA form a membrane-associated oxidoreductase complex (MRC) that physically links radical detoxification with cytosolic thiol homeostasis. Loss of any MRC component correlated with defective recycling of mycothiol and accumulation of cellular oxidative damage. This previously uncharacterized coordination between oxygen radical detoxification and thiol homeostasis is required to overcome the oxidative environment Mtb encounters in the host
Endothelin-Receptor Antagonists beyond Pulmonary Arterial Hypertension: Cancer and Fibrosis.
The endothelin axis and in particular the two endothelin receptors, ETA and ETB, are targets for therapeutic intervention in human diseases. Endothelin-receptor antagonists are in clinical use to treat pulmonary arterial hypertension and have been under clinical investigation for the treatment of several other diseases, such as systemic hypertension, cancer, vasospasm, and fibrogenic diseases. In this Perspective, we review the molecules that have been evaluated in human clinical trials for the treatment of pulmonary arterial hypertension, as well as other cardiovascular diseases, cancer, and fibrosis. We will also discuss the therapeutic consequences of receptor selectivity with regard to ETA-selective, ETB-selective, or dual ETA/ETB antagonists. We will also consider which chemical characteristics are relevant to clinical use and the properties of molecules necessary for efficacy in treating diseases against which known molecules displayed suboptimal efficacy
Towards a Unified Approach of Social Justice: Merging Tradition and Modernity in Public Policy Making in India
Myocardial Injury, Obesity, and the Obesity Paradox
To examine whether pre-heart failure (HF) myocardial injury explains the differential mortality after HF across weight categories
Common carotid artery intima-media thickness is as good as carotid intima-media thickness of all carotid artery segments in improving prediction of coronary heart disease risk in the Atherosclerosis Risk in Communities (ARIC) study
Carotid intima–media thickness (CIMT) and plaque information can improve coronary heart disease (CHD) risk prediction when added to traditional risk factors (TRF). However, obtaining adequate images of all carotid artery segments (A-CIMT) may be difficult. Of A-CIMT, the common carotid artery intima–media thickness (CCA-IMT) is relatively more reliable and easier to measure. We evaluated whether CCA-IMT is comparable to A-CIMT when added to TRF and plaque information in improving CHD risk prediction in the Atherosclerosis Risk in Communities (ARIC) study
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