28 research outputs found
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Modeling and forecasting of cooling and electricity load demand
The objective of this paper is to extend a statistical approach to effectively provide look-ahead forecasts for cooling and electricity demand load. Our proposed model is a generalized form of a Cochrane-Orcutt estimation technique that combines a multiple linear regression model and a seasonal autoregressive moving average model. The proposed model is adaptive so that it updates forecast values every time that new information on cooling and electricity load is received. Therefore, the model can simultaneously take advantage of two statistical methods, time series, and linear regression in an adaptive way. The effectiveness of the proposed forecast model is shown through a use case. The example utilizes the proposed approach for economic dispatching of a combined cooling, heating and power (CCHP) plant at the University of California, Irvine. The results reveal the effectiveness of the proposed forecast model
Influence of biotic vs abiotic processes on the genesis of non-marine carbonates along the Cameroon Volcanic Line (Cameroon) and palaeofluid provenance
Continental spring carbonates are perfect examples of the interaction of biotic and abiotic processes, and they preserve evidence of the velocity of the flow and the chemical composition of the spring water. This study focuses on non-marine carbonates from fossil and active springs from the Bongongo and Ngol areas along the Cameroon Volcanic Line in South-West Cameroon. Here, hydrothermal fluids reach the surface giving rise to small thermal springs, with temperatures between 31 and 49°C, and streams creating waterfalls, terracettes and barrage carbonate deposits. Petrographic analyses of these carbonates revealed that they are made up of stacked laminae of fibrous coarse crystals of low-Mg calcite and laminae of alternate microsparite and micrite. The fibrous coarsely crystalline calcite, often with feather-like fabric, grows from thin layers of micrite and peloids. Filaments of putative microbial origin are preserved within this peloidal micrite. The laminated microsparite and micrite microfacies is characterised by an intricate mesh of hollow filaments of microbial origin. The long feather-like crystals of calcite formed in fast-flowing water where the enhanced CO2 degassing has favoured the precipitation of CaCO3. The laminated micrite and microsparite, on the other hand, are probably formed in ponds where degassing and CO2 removal was lower and the calcite precipitation was fostered by microbial activity. The fast-forming carbonates show higher Ce contents and very low total rare earth elements, revealing a preferential uptake of Ce with respect to other rare earth elements. This process would explain the positive or null Ce anomaly in continental spring carbonates elsewhere. The geochemical composition of these carbonates can be used as proxy for the characterisation of fluid/rock interactions between the groundwater and the substratum and for the characterisation of the sources of calcium and other elements that constitute tufa and travertines. The samples from Ngol are characterised by light rare earth element enrichment while those from Bongongo are overall enriched in heavy rare earth elements. Carbonates from both localities have a strong positive Eu anomaly (>4), suggesting a contribution from deep-seated, hydrothermal, crustal fluids in contact with volcanic rocks and the breakdown of plagioclase from the Cameroon Volcanic Line alkali basalts
A new method for coupling glucose dehydrogenase to glass tubes activated with titanium tetrachloride
Analysis of CD8+ T-Cell-Mediated Inhibition of Hepatitis C Virus Replication Using a Novel Immunological Model
Virus-specific CD8+ T cells are required for the control of hepatitis C virus (HCV) infection. We investigated the extent to which different effector functions of CD8+ T cells contribute to the inhibition of viral replication.
Methods
We developed a novel immunologic model by stably transducing the HLA-A2 gene into the replicon system, matching the epitope sequence of the replicon to the sequence targeted by an HCV-specific CD8+ T-cell clone. Luciferase activity was then measured to quantitate HCV RNA replication.
Results
HCV-specific CD8+ T cells strongly inhibited viral replication, through cytolytic and noncytolytic mechanisms, in a dose-dependent manner. HCV replication was almost completely inhibited at an effector-to-target ratio of 1:1 with significant cytotoxicity; however, >95% viral inhibition occurred at ratios as low as 1:100. Importantly, no cytotoxicity was observed at low effector-to-target ratios, indicating a dominant effect of noncytolytic effector functions that was confirmed by Transwell experiments. Neutralization experiments revealed that interferon gamma mediates the noncytolytic inhibition.
Conclusions
Only a very few HCV-specific CD8+ T cells are required to inhibit HCV replication; inhibition occurs primarily by noncytolytic effector functions