4,011 research outputs found
Teaching language to hearing impaired children who have had no previous language experience
This paper purports to give (1) a systematic review of the background and theoretical development leading to the evolvement of the modern approach of language instruction for the hearing impaired child, and (2) a comparison of the grammatical and the developmental schools from the instructional point of view
Response to Ofgem consultation on targeted charging review: minded to decision and draft impact assessment
The authors welcome the opportunity to respond to Ofgem consultation on the best way of setting the transmission and distribution residual charges. We agree with Ofgem’s basic approach to fairness, which reflects our own assessment of fairness in distribution charges in a more general context, prepared for BEUC. 1 We also agree that a major principle behind recovering costs which are ‘legacy’ rather than forward looking costs, as in the Ofgem consultation, should be to distort consumption and investment decisions as little as possible. Our report majors on domestic customers, most of whom are more likely to alter their demand than to decide to leave the network altogether as a result of price changes. Therefore we agree that the principle of least distortion, as well as the other criteria outlined by Ofgem (in particular practicality and proportionality) indicate that a per customer charge is an appropriate basis for ‘residual charges’. We do not comment specifically on Embedded Benefits, but agree that similar principles should apply
Fast integral equation methods for the modified Helmholtz equation
We present a collection of integral equation methods for the solution to the
two-dimensional, modified Helmholtz equation, u(\x) - \alpha^2 \Delta u(\x) =
0, in bounded or unbounded multiply-connected domains. We consider both
Dirichlet and Neumann problems. We derive well-conditioned Fredholm integral
equations of the second kind, which are discretized using high-order, hybrid
Gauss-trapezoid rules. Our fast multipole-based iterative solution procedure
requires only O(N) or operations, where N is the number of nodes
in the discretization of the boundary. We demonstrate the performance of the
methods on several numerical examples.Comment: Published in Computers & Mathematics with Application
Development of an animal-component free insect medium for the Baculovirus Expression Vector System (BEVS)
Insect cells derived from Spodoptera frugiperda have been widely used with the baculovirus expression vector system (BEVS) for the production of recombinant proteins and adeno-associated viruses (AAVs) due to their ease of culture, scalability in high cell density suspension cultures, and high protein expression levels. Traditionally, insect cells are cultured in an undefined medium containing yeast hydrolysate and cod liver oil, however, there is an increasing push to use chemically defined, animal-component free medium to minimize any potential contaminants and decrease lot-to-lot variability while maintaining high cell growth and production. In this case study, an animal-component free insect medium was developed utilizing Rational Culture Media DesignTM and evaluated with Sf9 cells. Using a traditional formulation as a starting point, the final medium was developed by optimizing multiple nutrient groups in the basal medium, replacing the animal-derived components, and screening several yeast hydrolysate sources. By utilizing multifactor design of experiment software, various nutrient groups were screened including amino acids, vitamins, and metals. The metals group was identified to have the most impact on cell growth and productivity, and therefore concentrations of metal components were further optimized. In addition, the animal-derived components in the starting formulation, cod liver oil and cholesterol, were replaced with animal-component free fatty acids and synthetic cholesterol, respectively. The concentrations of these components were optimized to achieve better growth performance and production while also sustaining formulation stability and streamlining manufacturing processes. Finally, yeast hydrolysate is a well-known, undefined component that is crucial for insect cell growth and productivity. To minimize lot-to-lot variability, the yeast hydrolysate concentration was significantly lowered, and multiple yeast hydrolysate sources and lots were evaluated to determine the highest quality source. As a result, an animal-component free insect medium was developed that had improved growth performance and comparable productivity to a widely used commercially available animal-derived medium
A market approach to siting transmission facilities in Minnesota and North Dakota
Thesis. 1977. M.C.P.--Massachusetts Institute of Technology. Dept. of Urban Studies and Planning.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH.Includes bibliographical references.by Catherine Lu.M.C.P
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Mixed Spices at Culinary Doses Have Prebiotic Effects in Healthy Adults: A Pilot Study.
Spices were used as food preservatives prior to the advent of refrigeration, suggesting the possibility of effects on microbiota. Previous studies have shown prebiotic activities in animals and in vitro, but there has not been a demonstration of prebiotic or postbiotic effects at culinary doses in humans. In this randomized placebo-controlled study, we determined in twenty-nine healthy adults the effects on the gut microbiota of the consumption daily of capsules containing 5 g of mixed spices at culinary doses by comparison to a matched control group consuming a maltodextrin placebo capsule. The 16S ribosomal RNA sequencing data were used for microbial characterization. Spice consumption resulted in a significant reduction in Firmicutes abundance (p < 0.033) and a trend of enrichment in Bacteroidetes (p < 0.097) compared to placebo group. Twenty-six operational taxonomic units (OTUs) were different between the spice and placebo groups after intervention. Furthermore, there was a significant negative correlation between fecal short-chain fatty acid propionate concentration and Firmicutes abundance in spice intervention group (p < 0.04). The production of individual fecal short-chain fatty acid was not significantly changed by spice consumption in this study. Mixed spices consumption significantly modified gut microbiota, suggesting a prebiotic effect of spice consumption at culinary doses
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European mtDNA Variants Are Associated With Differential Responses to Cisplatin, an Anticancer Drug: Implications for Drug Resistance and Side Effects.
Background: Cisplatin, a powerful antitumor agent, causes formation of DNA adducts, and activation of apoptotic pathways. Presently, cisplatin resistance develops in up to 70% of patients but the underlying molecular mechanism(s) are unclear and there are no markers to determine which patients will become resistant. Mitochondria play a significant role not only in energy metabolism but also retrograde signaling (mitochondria to nucleus) that modulates inflammation, complement, and apoptosis pathways. Maternally inherited mitochondrial (mt) DNA can be classified into haplogroups representing different ethnic populations that have diverse susceptibilities to diseases and medications. Methods: Transmitochondrial cybrids, where all cell lines possess identical nuclear genomes but either the H (Southern European) or J (Northern European) mtDNA haplogroups, were treated with cisplatin and analyzed for differential responses related to viability, oxidative stress, and expression levels of genes associated with cancer, cisplatin-induced nephrotoxicity and resistance, apoptosis and signaling pathways. Results: The cisplatin-treated-J cybrids showed greater loss of cell viability along with lower levels of reactive oxygen species and mitochondrial membrane potential compared to cisplatin-treated-H cybrids. After cisplatin treatment, J cybrids showed increased gene expression of BAX, CASP3, and CYP51A, but lower levels of SFRP1 compared to untreated-J cybrids. The cisplatin-treated-H cybrids had elevated expression of CDKN1A/P21, which has a role in cisplatin toxicity, compared to untreated-H cybrids. The cisplatin-treated H had higher transcription levels of ABCC1, DHRS2/HEP27, and EFEMP1 compared to cisplatin-treated-J cybrids. Conclusions: Cybrid cell lines that contain identical nuclei but either H mtDNA mitochondria or J mtDNA mitochondria respond differently to cisplatin treatments suggesting involvement of the retrograde signaling (from mitochondria to nucleus) in the drug-induced cell death. Varying toxicities and transcription levels of the H vs. J cybrids after cisplatin treatment support the hypothesis that mtDNA variants play a role in the expression of genes affecting resistance and side effects of cisplatin
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