349 research outputs found
Time and location differentiated NOX control in competitive electricity markets using cap-and-trade mechanisms
Due to variations in weather and atmospheric chemistry, the timing and location of nitrogen oxide (NOX) reductions determine their effectiveness in reducing ground-level ozone, which adversely impacts human health. Electric generating plants are the primary stationary sources of NOX in most regions of the United States. In the Eastern U.S. they are subject to a summertime NOX cap and trade program that is not well matched to the time and locational impacts of NOX on ozone formation. We hypothesize that the integration of weather and atmospheric chemistry forecasting, a cap and trade system in which the "exchange rates" for permits can be varied by time and location based on these forecasts, and its application to a competitive wholesale electricity market, can achieve ozone standards more efficiently. To demonstrate the potential for reductions in NOX emissions in the short run, we simulate the magnitude of NOX reductions that can be achieved at various locations and times as a consequence of redispatch of generating units in the "classic" PJM region taking supply-demand balance constraints and network congestion into account. We report simulations using both a zonal model and an optimal power flow model.(cont.) We also estimate the relationship between the level NOX emission prices, competitive market responses to different levels of NOX prices, and the associated reductions in NOx emissions. The estimated maximum potential reductions, which occur at NOX prices of about $125,000/ton, are about 8 tons (20%) hourly in peak electricity demand hours and about 10 tons (50%) in average demand hours. We find that network constraints have little effect on the magnitude of the reductions in NOX emissions.Funding provided jointly by the U.S. Environmental Protection Agency (EPA) and the National Oceanic and Atmospheric Administration (NOAA); as well as the CEEP
Teacher Preferences for Alternative School Site Administrative Models
Public school teachers with high leadership potential who stated that they had no interest in being school principals were surveyed on their attitudes about six alternative school site administrative organizational models. Of the 391 teachers surveyed, 53% identified the Co-Principal model as the preferred school site administrative structure. In order of preference were the Co-Principal model, the Principal/Business Manager model, the Multi-Principal model, the Principal/Associate Principal model, the Principal Teacher/Principal Administrator model, and the Principal/Educational Specialist model. Among teachers at the elementary, middle, and secondary levels, the only significant difference was on the Multi-Principal model, which was favored more by middle and high school teachers than by elementary teachers. The findings suggest that teachers who had previously reported a lack of interest in becoming school principals might be interested in the position if the organizational structure of the school site were different from the traditional organizational model
Exploring autophagy with Gene Ontology.
Autophagy is a fundamental cellular process that is well conserved among eukaryotes. It is one of the strategies that cells use to catabolize substances in a controlled way. Autophagy is used for recycling cellular components, responding to cellular stresses and ridding cells of foreign material. Perturbations in autophagy have been implicated in a number of pathological conditions such as neurodegeneration, cardiac disease and cancer. The growing knowledge about autophagic mechanisms needs to be collected in a computable and shareable format to allow its use in data representation and interpretation. The Gene Ontology (GO) is a freely available resource that describes how and where gene products function in biological systems. It consists of 3 interrelated structured vocabularies that outline what gene products do at the biochemical level, where they act in a cell and the overall biological objectives to which their actions contribute. It also consists of \u27annotations\u27 that associate gene products with the terms. Here we describe how we represent autophagy in GO, how we create and define terms relevant to autophagy researchers and how we interrelate those terms to generate a coherent view of the process, therefore allowing an interoperable description of its biological aspects. We also describe how annotation of gene products with GO terms improves data analysis and interpretation, hence bringing a significant benefit to this field of study. Autophagy 2018; 14(3):419-436
Exploring autophagy with Gene Ontology.
Autophagy is a fundamental cellular process that is well conserved among eukaryotes. It is one of the strategies that cells use to catabolize substances in a controlled way. Autophagy is used for recycling cellular components, responding to cellular stresses and ridding cells of foreign material. Perturbations in autophagy have been implicated in a number of pathological conditions such as neurodegeneration, cardiac disease and cancer. The growing knowledge about autophagic mechanisms needs to be collected in a computable and shareable format to allow its use in data representation and interpretation. The Gene Ontology (GO) is a freely available resource that describes how and where gene products function in biological systems. It consists of 3 interrelated structured vocabularies that outline what gene products do at the biochemical level, where they act in a cell and the overall biological objectives to which their actions contribute. It also consists of \u27annotations\u27 that associate gene products with the terms. Here we describe how we represent autophagy in GO, how we create and define terms relevant to autophagy researchers and how we interrelate those terms to generate a coherent view of the process, therefore allowing an interoperable description of its biological aspects. We also describe how annotation of gene products with GO terms improves data analysis and interpretation, hence bringing a significant benefit to this field of study. Autophagy 2018 Feb 17; 1-18
Efek Terapi Perilaku, Terapi Kognitif Perilaku dan Psikoedukasi Keluarga pada Klien Halusinasi Menggunakan Pendekatan Teori Berubah Kurt Lewin
Hallucination is the most nursing diagnose found in mental health hospital. The purpose of this scientific report is to determine the effect of behavioral therapy, cognitive behavioral therapy and family psychoeducation therapy on client’s skill and signs and symptoms of hallucination using Kurt Lewin’s Change Theory Model approach. The method used is the application of behavioral therapy, cognitive behavioral therapy and family psychoeducation to 16 clients with hallucination. Clients are grouped into three groups: 8 clients were given behavioral therapy, 4 clients were given behavioral therapy and family psychoeducation, and 4 clients were given cognitive behavioral therapy. The results showed cognitive behavior therapy increases client’s skills and family’s skills but reduces most signs and symptoms of hallucination than clients who received behavioral therapy and psychoeducation or client who received behavior therapy only. Cognitive behavior therapy is strongly recommended in treating client with hallucination
Regular Topologies for Gigabit Wide-Area Networks
In general terms, this project aimed at the analysis and design of techniques for very high-speed networking. The formal objectives of the project were to: (1) Identify switch and network technologies for wide-area networks that interconnect a large number of users and can provide individual data paths at gigabit/s rates; (2) Quantitatively evaluate and compare existing and proposed architectures and protocols, identify their strength and growth potentials, and ascertain the compatibility of competing technologies; and (3) Propose new approaches to existing architectures and protocols, and identify opportunities for research to overcome deficiencies and enhance performance. The project was organized into two parts: 1. The design, analysis, and specification of techniques and protocols for very-high-speed network environments. In this part, SRI has focused on several key high-speed networking areas, including Forward Error Control (FEC) for high-speed networks in which data distortion is the result of packet loss, and the distribution of broadband, real-time traffic in multiple user sessions. 2. Congestion Avoidance Testbed Experiment (CATE). This part of the project was done within the framework of the DARTnet experimental T1 national network. The aim of the work was to advance the state of the art in benchmarking DARTnet's performance and traffic control by developing support tools for network experimentation, by designing benchmarks that allow various algorithms to be meaningfully compared, and by investigating new queueing techniques that better satisfy the needs of best-effort and reserved-resource traffic. This document is the final technical report describing the results obtained by SRI under this project. The report consists of three volumes: Volume 1 contains a technical description of the network techniques developed by SRI in the areas of FEC and multicast of real-time traffic. Volume 2 describes the work performed under CATE. Volume 3 contains the source code of all software developed under CATE
Toxoplasma ceramide synthases: Gene duplication, functional divergence, and roles in parasite fitness.
Toxoplasma gondii is an obligate, intracellular apicomplexan protozoan parasite of both humans and animals that can cause fetal damage and abortion and severe disease in the immunosuppressed. Sphingolipids have indispensable functions as signaling molecules and are essential and ubiquitous components of eukaryotic membranes that are both synthesized and scavenged by the Apicomplexa. Ceramide is the precursor for all sphingolipids, and here we report the identification, localization and analyses of the Toxoplasma ceramide synthases TgCerS1 and TgCerS2. Interestingly, we observed that while TgCerS1 was a fully functional orthologue of the yeast ceramide synthase (Lag1p) capable of catalyzing the conversion of sphinganine to ceramide, in contrast TgCerS2 was catalytically inactive. Furthermore, genomic deletion of TgCerS1 using CRISPR/Cas-9 led to viable but slow-growing parasites indicating its importance but not indispensability. In contrast, genomic knock out of TgCerS2 was only accessible utilizing the rapamycin-inducible Cre recombinase system. Surprisingly, the results demonstrated that this "pseudo" ceramide synthase, TgCerS2, has a considerably greater role in parasite fitness than its catalytically active orthologue (TgCerS1). Phylogenetic analyses indicated that, as in humans and plants, the ceramide synthase isoforms found in Toxoplasma and other Apicomplexa may have arisen through gene duplication. However, in the Apicomplexa the duplicated copy is hypothesized to have subsequently evolved into a non-functional "pseudo" ceramide synthase. This arrangement is unique to the Apicomplexa and further illustrates the unusual biology that characterize these protozoan parasites. [Abstract copyright: © 2023 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.
Holocene sediment distribution on the inner continental shelf of northeastern South Carolina : implications for the regional sediment budget and long-term shoreline response
This paper is not subject to U.S. copyright. The definitive version was published in Continental Shelf Research 56 (2013): 56-70, doi:10.1016/j.csr.2013.02.004.High-resolution geophysical and sediment sampling surveys were conducted offshore of the Grand Strand, South Carolina to define the shallow geologic framework of the inner shelf. Results are used to identify and map Holocene sediment deposits, infer sediment transport pathways, and discuss implications for the regional coastal sediment budget.
The thickest deposits of Holocene sediment observed on the inner shelf form shoal complexes composed of moderately sorted fine sand, which are primarily located offshore of modern tidal inlets. These shoal deposits contain ∼67 M m3 of sediment, approximately 96% of Holocene sediment stored on the inner shelf. Due to the lack of any significant modern fluvial input of sand to the region, the Holocene deposits are likely derived from reworking of relict Pleistocene and older inner-shelf deposits during the Holocene marine transgression. The Holocene sediments are concentrated in the southern part of the study area, due to a combination of ancestral drainage patterns, a regional shift in sediment supply from the northeast to the southwest in the late Pleistocene, and proximity to modern inlet systems. Where sediment is limited, only small, low relief ridges have formed and Pleistocene and older deposits are exposed on the seafloor. The low-relief ridges are likely the result of a thin, mobile veneer of sediment being transported across an irregular, erosional surface formed during the last transgression.
Sediment textural trends and seafloor morphology indicate a long-term net transport of sediment to the southwest. This is supported by oceanographic studies that suggest the long-term sediment transport direction is controlled by the frequency and intensity of storms that pass through the region, where low pressure systems yield net along-shore flow to the southwest and a weak onshore component.
Current sediment budget estimates for the Grand Strand yield a deficit for the region. Volume calculations of Holocene deposits on the inner shelf suggest that there is sufficient sediment to balance the sediment budget and provide a source of sediment to the shoreline. Although the processes controlling cross-shelf sediment transport are not fully understood, in sediment-limited environments such as the Grand Strand, erosion of the inner shelf likely contributes significant sediment to the beach system
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