269 research outputs found

    An Optimal Power Flow Model to Guide National Grid Expansion in Ethiopia for Groundwater Irrigation

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    Ethiopia is a low-income country with an agrarian based economy that is susceptible to shocks, such as drought. Expanding groundwater irrigation (GWI) technologies can increase agricultural yields by providing a water source for crop production. There are upcoming mega-dams– the Grand Ethiopian Renaissance Dam, Genale Dawa III, and Koysha – that will triple the generation capacity and can supply electricity for GWI. To utilize this generation capacity, the transmission capacity of the national electricity grid, or Interconnected System (ICS), needs to expand into regions with high GWI potential. This thesis builds a regional-scale linear optimal power flow model to guide cost-optimal generation operations and transmission expansion of the ICS to satisfy electricity demand from GWI. The model determines cost-optimal generation and transmission expansion for a baseline case and five scenarios that consider combinations of present and future estimations of internal demand, including domestic regional demand and electricity demand for GWI (low irrigation; high irrigation), and international export demand (current exports; future exports). Compared to the Baseline Scenario, seasonal capacity factors for electricity generation output in the five model scenarios increased or remained the same depending on the location of demand increase. Results from four of the scenarios where internal and/or external demand increases indicate varying levels of expansion for five transmission lines in the regional network. The Ethiopian Electric Power Company (EEPCo) has a planned expansion of 1090 MW across these same five lines. All scenarios with higher domestic regional demand than the present baseline independent of irrigation and export changes surpass the transmission expansion planned by EEPCo, suggesting that the current expansion plan is not cost optimal. This thesis contributes to the literature by modeling endogenous infrastructure decisions under different scenarios for internal and external demand. Modeling such decisions requires integrating the electricity network with energy demands from the agricultural sector and international export markets. The thesis builds a framework for answering research questions at the intersection of such topics that is broadly applicable to low-income countries. Further, the thesis provides a systematic framework for modeling electricity network infrastructure in data-poor settings through estimation, verification, and incorporation of unavailable data

    Distributed Device Bus

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    Peripheral devices are hardware components that are connected to a computer and they supplement the functionality of a computer. Over the years, a huge improvement has been observed both in variety and capabilities of peripheral devices. Starting from the input/output and storage devices of early days, today's peripheral devices support all aspects of a computer, with peripherals like Graphical Processing Units (GPUs) even supplementing the computational capabilities of a processor. At the same time, the support for peripheral devices in computers has vastly improved. While the earlier computers only supported static configuration of devices, the plug-and-play capabilities in present day computers allow devices to be added or removed at run time, thus reducing the complexity of managing peripheral devices. Today, it is not an exaggeration to state that, beyond the computational capability of a computer, it is the peripheral devices that define the user experience. With the advancements in networking and distributed computing, the definition of what constitutes a computer has been blurred: Mainframes and Supercomputing clusters support batch processing, where processors/cores are treated as resources, and number of processors/cores available for a specific computation can be requested on demand. With cloud computing, users access services hosted across the Internet. However, usage models for peripheral devices have not caught up accordingly. For the most part, Peripheral devices are still limited to the computers they are physical attached to. Device virtualization solutions exist that can extend the device protocols over the network, enabling users to access devices connected to a different computer. However, these device virtualization solutions still need direct access to both the computer that has the device plugged in (Device Server) and to the computer that intends to use the device (Device Client) and they do not support remote plug-and-play. So, there is a need for a device consolidation framework that supports new device usage models that are in line with the evolving models of computation. In this thesis, we propose a framework called "Distributed Device Bus", which extends the concept of a conventional peripheral bus to include in its scope, the ports of all the computers that are connected over a network. Like a peripheral bus, a Distributed Device Bus is also associated with a computer called Master node. A Distributed Device Bus supports dynamic addition/deletion of ports and each of these ports can physically belong to any computer in the network. Computers that contribute ports to a Distributed Device Bus are called Provider nodes. A device plugged into any port that is assigned to a Distributed Device Bus is immediately made accessible to applications on master node. This device consolidation framework treats devices as a resource and access to a device is configurable rather than being limited to the computer the device is physically attached to

    Rare Disease Advocacy Groups and Their Significance in Diagnosis, Management, Treatment, and Prevention of Rare Diseases

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    Rare diseases are those diseases that are not seen frequently in a population. There are about 7000 rare diseases that have been identified worldwide, and 80% of them are caused by genetic changes. Since a small number of individuals are affected with rare diseases, most clinicians are not aware of such diseases, and thus, they remain undiagnosed and untreated. Awareness regarding such diseases is essential to train clinicians to diagnose individuals affected with these disorders and to develop National/International Registries, which will serve to give information about the disease prevalence, its natural course, treatment, and management options available, to the medical fraternity. Patient advocacy groups play a remarkable and unique role in forming the collective voice of individuals living with rare diseases. They help in the identification, diagnosis, management, treatment, and prevention of such diseases. Advocacy Groups form collaborative partnerships with scientists studying such rare diseases, clinicians managing these diseases, pharmaceutical companies developing drugs, and Government officials overseeing and policy makers implementing medical regulatory processes. Thus, advocacy groups play a key role in helping patients and families with rare diseases

    Cinnamon Polyphenol Extract Inhibits Hyperlipidemia and Inflammation by Modulation of Transcription Factors in High-Fat Diet-Fed Rats

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    We evaluated the effects of cinnamon polyphenol extract on hepatic transcription factors expressions including SREBP-1c and LXR-α in rats fed high fat diet (HFD). Twenty-eight Wistar rats were allocated into four groups: (i) normal control: animals fed with normal chow; (ii) cinnamon: animals supplemented with cinnamon polyphenol; (iii) HFD: animals fed a high-fat diet; and (iv) HFD + cinnamon: animals fed a high-fat diet and treated with cinnamon polyphenol. Obesity was linked to hyperglycemia, hyperlipidemia, and oxidative stress as imitated by elevated serum glucose, lipid profile, and serum and liver malondialdehyde (MDA) concentrations. Cinnamon polyphenol decreased body weight, visceral fat, liver weight and serum glucose and insulin concentrations, liver antioxidant enzymes, and lipid profile (P<0.05) and reduced serum and liver MDA concentration compared to HFD rats (P<0.05). Cinnamon polyphenol also suppressed the hepatic SREBP-1c, LXR-α, ACLY, FAS, and NF-κB p65 expressions and enhanced the PPAR-α, IRS-1, Nrf2, and HO-1 expressions in the HFD rat livers (P<0.05). In conclusion, cinnamon polyphenol reduces the hyperlipidemia, inflammation, and oxidative stress through activating transcription factors and antioxidative defense signaling pathway in HFD rat liver

    Genomic analysis of a lignocellulose degrading strain from the underexplored genus Meridianimaribacter

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    The genus Meridianimaribacter is one of the least-studied genera within Cytophaga-Flavobacteria. To date, no genomic analysis of Meridianimaribacter has beenreported. In this study, Meridianimaribacter sp. strain CL38, a lignocellulosedegrading halophile was isolated from mangrove soil. The genome of strain CL38was sequenced and analyzed. The assembled genome contains 17 contigs with 3.33Mbp, a GC content of 33.13% and a total of 2982 genes predicted. Lignocellulosedegrading enzymes such as cellulases (GH3, 5, 9, 16, 74 and 144), xylanases (GH43and CE4) and mannanases (GH5, 26, 27 and 130) are encoded in the genome.Furthermore, strain CL38 demonstrated its ability to decompose empty fruit bunch, alignocellulosic waste residue arising from palm oil industry. The genome informationcoupled with experimental studies confirmed the ability of strain CL38 to degradelignocellulosic biomass. Therefore, Meridianimaribacter sp. strain CL38, with itshalotolerance, could be useful for seawater based lignocellulosic biorefining

    Curcumin prevents muscle damage by regulating NF-kB and Nrf2 pathways and improves performance: an in vivo model

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    Purpose Exercise (Ex) increases reactive oxygen species and impairs antioxidant defense systems. Recent data suggest that curcumin (CW) possesses peroxisome proliferator-activated receptor gamma activity and anti-inflammatory properties. Therefore, this study was designed to investigate the effects of CW supplementation on Ex performance, endurance, and changes in serum and muscle proteins in rats after exhaustive Ex. Materials and methods Twenty-eight (28) male Wistar rats (age: 8 weeks and body weight: 180±20 g) were divided into four treatment groups: 1) control (C; no Ex), 2) C + CW (no Ex + CW), 3) C + Ex, and 4) C + Ex + CW (Ex + CW). CW was administered as 100 mg/kg CurcuWin®, providing 20 mg of curcuminoids daily for 6 weeks. A motor-driven rodent treadmill was used to carry out the Ex protocols. During a 5-day period, animals in chronic Ex groups were put through different regimens: day 1, 10 m/min for 10 minutes; day 2, 20 m/min for 10 minutes; day 3, 25 m/min for 10 minutes; day 4, 25 m/min for 20 minutes; and day 5, 25 m/min for 30 minutes. Animals were exercised at 25 m/min for 45 min/d for 5 d/wk for 6 weeks. Blood and muscle samples were analyzed for muscle markers, oxidative stress, and antioxidant markers. Results Lactate and muscle malondialdehyde levels decreased in the CW-treated groups (P<0.0001). However, activities of antioxidant enzyme levels increased in the CW-treated groups. Run to exhaustion (minutes) improved in the CW-treated groups. Muscle nuclear factor-κB (P<0.05) and heat shock protein 70 (P<0.05) levels were much lowered in the CW treated group followed by Ex group. In addition, muscle inhibitors of kappa B, peroxisome proliferator-activated receptor gamma coactivator 1-alpha, thioredoxin-1, sirtuin 1, nuclear factor (erythroid-derived 2)-like 2, and glucose transporter 4 protein levels in the Ex + CW group were higher than those in the control and Ex groups (P<0.05). Conclusion This study suggests that novel CW has the potential to help prevent muscle damage by regulating the nuclear factor-κB and nuclear factor (erythroid-derived 2)-like 2 pathways and improve the performance and nutritional values of CW

    Characterisation of a recombinant β-xylosidase (xylA) from Aspergillus oryzae expressed in Pichia pastoris

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    β-xylosidases catalyse the hydrolysis of short chain xylooligosaccharides from their non-reducing ends into xylose. In this study we report the heterologous expression of Aspergillus oryzae β-xylosidase (XylA) in Pichia pastoris under the control of the glyceraldehyde-3-phosphate dehydrogenase promoter. The recombinant enzyme was optimally active at 55°C and pH 4.5 with Km and Vmax values of 1.0 mM and 250 μmol min−1 mg−1 respectively against 4-nitrophenyl β-xylopyranoside. Xylose was a competitive inhibitor with a Ki of 2.72 mM, whereas fructose was an uncompetitive inhibitor reducing substrate binding affinity (Km) and conversion efficiency (Vmax). The enzyme was characterised to be an exo-cutting enzyme releasing xylose from the non-reducing ends of β-1,4 linked xylooligosaccharides (X2, X3 and X4). Catalytic conversion of X2, X3 and X4 decreased (Vmax and kcat) with increasing chain length

    Molecular genetics and phenotypic assessment of foxtail millet (Setaria italica (L.) P. Beauv.) landraces revealed remarkable variability of morpho-physiological, yield, and yield‐related traits

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    Foxtail millet (Setaria italica (L.) P. Beauv.) is highly valued for nutritional traits, stress tolerance and sustainability in resource-poor dryland agriculture. However, the low productivity of this crop in semi-arid regions of Southern India, is further threatened by climate stress. Landraces are valuable genetic resources, regionally adapted in form of novel alleles that are responsible for cope up the adverse conditions used by local farmers. In recent years, there is an erosion of genetic diversity. We have hypothesized that plant genetic resources collected from the semi-arid climatic zone would serve as a source of novel alleles for the development of climate resilience foxtail millet lines with enhanced yield. Keeping in view, there is an urgent need for conservation of genetic resources. To explore the genetic diversity, to identify superior genotypes and novel alleles, we collected a heterogeneous mixture of foxtail millet landraces from farmer fields. In an extensive multi-year study, we developed twenty genetically fixed foxtail millet landraces by single seed descent method. These landraces characterized along with four released cultivars with agro-morphological, physiological, yield and yield-related traits assessed genetic diversity and population structure. The landraces showed significant diversity in all the studied traits. We identified landraces S3G5, Red, Black and S1C1 that showed outstanding grain yield with earlier flowering, and maturity as compared to released cultivars. Diversity analysis using 67 simple sequence repeat microsatellite and other markers detected 127 alleles including 11 rare alleles, averaging 1.89 alleles per locus, expected heterozygosity of 0.26 and an average polymorphism information content of 0.23, collectively indicating a moderate genetic diversity in the landrace populations. Euclidean Ward’s clustering, based on the molecular markers, principal coordinate analysis and structure analysis concordantly distinguished the genotypes into two to three sub-populations. A significant phenotypic and genotypic diversity observed in the landraces indicates a diverse gene pool that can be utilized for sustainable foxtail millet crop improvement
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