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Earnings forecasts have received a great deal of attention, much of which has centered on the comparative accuracy of judgmental and objective forecasting methods. Recently, studies have focused on the use of combinations of subjective and objective forecasts to improve forecast accuracy. This research offers an extension on this theme by subjectively modifying an objective forecast. Specifically, ARIMA forecasts are judgmentally adjusted by analysts using a structured approach based on Saaty's (1980) analytic hierarchy process. The results show that the accuracy of the unadjusted objective forecasts can be improved when judgmentally adjusted. 相似文献
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Su X Chakravarti D Cho MS Liu L Gi YJ Lin YL Leung ML El-Naggar A Creighton CJ Suraokar MB Wistuba I Flores ER 《Nature》2010,467(7318):986-990
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Blanche PA Bablumian A Voorakaranam R Christenson C Lin W Gu T Flores D Wang P Hsieh WY Kathaperumal M Rachwal B Siddiqui O Thomas J Norwood RA Yamamoto M Peyghambarian N 《Nature》2010,468(7320):80-83
Holography is a technique that is used to display objects or scenes in three dimensions. Such three-dimensional (3D) images, or holograms, can be seen with the unassisted eye and are very similar to how humans see the actual environment surrounding them. The concept of 3D telepresence, a real-time dynamic hologram depicting a scene occurring in a different location, has attracted considerable public interest since it was depicted in the original Star Wars film in 1977. However, the lack of sufficient computational power to produce realistic computer-generated holograms and the absence of large-area and dynamically updatable holographic recording media have prevented realization of the concept. Here we use a holographic stereographic technique and a photorefractive polymer material as the recording medium to demonstrate a holographic display that can refresh images every two seconds. A 50?Hz nanosecond pulsed laser is used to write the holographic pixels. Multicoloured holographic 3D images are produced by using angular multiplexing, and the full parallax display employs spatial multiplexing. 3D telepresence is demonstrated by taking multiple images from one location and transmitting the information via Ethernet to another location where the hologram is printed with the quasi-real-time dynamic 3D display. Further improvements could bring applications in telemedicine, prototyping, advertising, updatable 3D maps and entertainment. 相似文献
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The paper reports results of an experiment conducted to evaluate subjective versus objective combination of forecasts. The subjects were undergraduate students at Texas A&M. The students forecasted two different types of time series. The results found show that the subjective combination of forecasts improves their accuracy as compared with individual efforts. Four ex-ante weighting methods were also used to combine the forecasts. They all improve the accuracy of the forecasts. The best results, though, were from the subjective combination of forecasts. 相似文献
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The tumour-suppressor gene p53 is frequently mutated in human cancers and is important in the cellular response to DNA damage. Although the p53 family members p63 and p73 are structurally related to p53, they have not been directly linked to tumour suppression, although they have been implicated in apoptosis. Given the similarity between this family of genes and the ability of p63 and p73 to transactivate p53 target genes, we explore here their role in DNA damage-induced apoptosis. Mouse embryo fibroblasts deficient for one or a combination of p53 family members were sensitized to undergo apoptosis through the expression of the adenovirus E1A oncogene. While using the E1A system facilitated our ability to perform biochemical analyses, we also examined the functions of p63 and p73 using an in vivo system in which apoptosis has been shown to be dependent on p53. Using both systems, we show here that the combined loss of p63 and p73 results in the failure of cells containing functional p53 to undergo apoptosis in response to DNA damage. 相似文献
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R. S. B. Cordeiro J. Assreuy Filho C. A. Flores F. Q. Cunha M. A. Martins H. N. Vasconcelos 《Cellular and molecular life sciences : CMLS》1984,40(3):301-302
Summary Mice inoculated withPlasmodium berghei developed a drastic and significant pulmonary edema. Treatment of animals with phenoxybenzamine rendered mice hyporeactive to this physiopathological alteration.This work was supported by a grant aided by «Conselho Nacional de Desenvolvimento Científico e Tecnológico» (CNPq, Brasil). Presented in preliminary form at the XIX Annual Meeting of the Brazilian Society of Tropical Medicine, Rio de Janeiro, R. J., February 20, 1983.Acknowledgments. We thank Mr Antonio Fernando de P. Oliveira and Solano S. Martins for their excellent technical help. 相似文献
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Telomerase-deficient mice with short telomeres are resistant to skin tumorigenesis 总被引:25,自引:0,他引:25
Inhibition of telomerase is proposed to limit the growth of cancer cells by triggering telomere shortening and cell death. Telomere maintenance by telomerase is sufficient, in some cell types, to allow immortal growth. Telomerase has been shown to cooperate with oncogenes in transforming cultured primary human cells into neoplastic cells, suggesting that telomerase activation contributes to malignant transformation. Moreover, telomerase inhibition in human tumour cell lines using dominant-negative versions of TERT leads to telomere shortening and cell death. These findings have led to the proposition that telomerase inhibition may result in cessation of tumour growth. The absence of telomerase from most normal cells supports the potential efficacy of anti-telomerase drugs for tumour therapy, as its inhibition is unlikely to have toxic effects. Mice deficient for Terc RNA (encoding telomerase) lack telomerase activity, and constitute a model for evaluating the role of telomerase and telomeres in tumourigenesis. Late-generation Terc-/- mice show defects in proliferative tissues and a moderate increase in the incidence of spontaneous tumours in highly proliferative cell types (lymphomas, teratocarcinomas). The appearance of these tumours is thought to be a consequence of chromosomal instability in these mice. These observations have challenged the expected effectiveness of anti-telomerase-based cancer therapies. Different cell types may nonetheless vary in their sensitivity to the chromosomal instability produced by telomere loss or to the activation of telomere-rescue mechanisms. Here we show that late-generation Terc-/- mice, which have short telomeres and are telomerase-deficient, are resistant to tumour development in multi-stage skin carcinogenesis. Our results predict that an anti-telomerase-based tumour therapy may be effective in epithelial tumours. 相似文献
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Tulapurkar ME Schäfer R Hanck T Flores RV Weisman GA González FA Reiser G 《Cellular and molecular life sciences : CMLS》2005,62(12):1388-1399
Extracellular nucleotides exert a large number of physiological effects through activation of P2Y receptors. We expressed rat P2Y2 (rP2Y2) receptor, tagged with green fluorescent protein (GFP) in HEK-293 cells and visualized receptor translocation in live cells by confocal microscopy. Functional receptor expression was confirmed by determining [Ca2+]i responses. Agonist stimulation caused a time-dependent translocation of the receptor from the plasma membrane to the cytoplasm. Rearrangement of the actin cytoskeleton was observed during agonist-mediated rP2Y2-GFP receptor internalization. Colocalization of the internalized receptor with early endosomes, clathrin and lysosomes was detected by confocal microscopy. The inhibition of receptor endocytosis by either high-density medium or chlorpromazine in the presence of UTP indicates that the receptor was internalized by the clathrin-mediated pathway. The caveolin- mediated pathway was not involved. Targeting of the receptor from endosomes to lysosomes seems to involve the proteasome pathway, because proteasomal inhibition increased receptor recycling back to the plasma membrane.Received 8 February 2005; received after revision 18 March 2005; accepted 11 April 2005 相似文献
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Peptide formation mediated by cyanate 总被引:2,自引:0,他引:2