1,573 research outputs found
Embodied Metaphors and Creative “Acts”
Creativity is a highly sought after skill. To inspire people’s creativity, prescriptive advice in the form of metaphors abound: We are encouraged to think outside the box, to consider the problem on one hand, then on the other hand, and to put two and two together to achieve creative breakthroughs. These metaphors suggest a connection between concrete bodily experiences and creative cognition. Inspired by recent advances on body-mind linkages under the emerging vernacular of embodied cognition, we explored for the first time whether enacting metaphors for creativity enhances creative problem-solving. In five studies, findings revealed that both physically and psychologically embodying creative metaphors promote fluency, flexibility, and/or originality in problem-solving. Going beyond prior research that focused primarily on the kind of embodiment that primes preexisting knowledge, we provide the first evidence that embodiment can also activate cognitive processes conducive for generating previously unknown ideas and connections
Preparation Process and Dielectric Properties of Ba(0.5)Sr(0.5)TiO3-P(VDF-CTFE) Nanocomposites
Ceramic-polymer 0-3 nanocomposites, in which nanosized Ba(0.5)Sr(0.5)TiO3 (BST) powders were used as ceramic filler and P(VDF-CTFE) 88/12 mol% [poly(vinylidene fluoridechlorotrifluoroethylene)] copolymer was used as matrix, were studied over a concentration range from 0 to 50 vol.% of BST powders. It is found that the solution cast composites are porous and a hot-press process can eliminate the porosity, which results in a dense composite film. Two different configurations used in the hot-press process are studied. Although there is no clear difference in the uniformity and microstructure of the composites prepared using these two configurations, the composite prepared using one configuration exhibit a higher dielectric constant with a lower loss. For the composite with 40 vol. BST, a dielectric constant of 70 with a loss of 0.07 at 1 kHz is obtained at room temperature. The composites exhibit a lower dielectric loss than the polymer matrix at high frequency. However, at low frequency, the composites exhibit a higher loss than the polymer matrix due to a low frequency relaxation process that appears in the composites. It is believed that this relaxation process is related to the interfacial layer formed between BST particle and the polymer matrix. The temperature dependence of the dielectric property of the composites was studied. It is found that the dielectric constant of these composites is almost independent of the temperature over a temperature range from 20 to 120 C. Key words: A. Polymer-matrix composites (PMCs); B. Electrical Properties; E. Casting; E. Heat treatment; Dielectric properties
Vascular endothelial growth factor restores delayed tumor progression in tumors depleted of macrophages
Genetic depletion of macrophages in Polyoma Middle T oncoprotein (PyMT)‐induced mammary tumors in mice delayed the angiogenic switch and the progression to malignancy. To determine whether vascular endothelial growth factor A (VEGF‐A) produced by tumor‐associated macrophages regulated the onset of the angiogenic switch, a genetic approach was used to restore expression of VEGF‐A into tumors at the benign stages. This stimulated formation of a high‐density vessel network and in macrophage‐depleted mice, was followed by accelerated tumor progression. The expression of VEGF‐A led to a massive infiltration into the tumor of leukocytes that were mostly macrophages. This study suggests that macrophage‐produced VEGF regulates malignant progression through stimulating tumor angiogenesis, leukocytic infiltration and tumor cell invasion
Positron emission tomography agent 2-deoxy-2-[(18)F]fluoro-D-glucose has a therapeutic potential in breast cancer
BACKGROUND: Novel approaches are needed for breast cancer patients in whom standard therapy is not effective. 2-Deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) was evaluated as a potential radiomolecular therapy agent in breast cancer animal models and, retrospectively, in patients with metastatic breast cancer. METHODS: Polyoma middle T antigen (PyMT) and mouse mammary tumor virus-NeuT transgenic mice with tumors 0.5–1 cm in diameter were imaged with (18)F-FDG, and tumor to liver ratios (TLRs) were calculated. The radiotoxicity of (18)F-FDG administration was determined in healthy mice. PyMT mice with small (0.15–0.17 cm) and large (more than 1 cm) tumors were treated with 2–4 mCi of (18)F-FDG, and control C3H/B6 mice with 3 mCi of (18)F-FDG. At 10 days after treatment the tumors and control mammary glands were analyzed for the presence of apoptotic and necrotic cells. Five patients with breast cancer and metastatic disease were evaluated and standardized uptake values (SUVs) in tumors, maximum tolerated dose, and the doses to the tumor were calculated. RESULTS: Doses up to 5 mCi proved to be non-radiotoxic to normal organs. The (18)F-FDG uptake in mouse tumors showed an average TLR of 1.6. The treatment of mice resulted in apoptotic cell death in the small tumors. Cell death through the necrotic pathway was seen in large tumors, and was accompanied by tumor fragmentation and infiltration with leukocytes. Normal mammary tissues were not damaged. A human (18)F-FDG dose delivering 200 rad to the red marrow (less than 5% damage) was calculated to be 4.76 Ci for a 70 kg woman, and the dose to the tumors was calculated to be 220, 1100 and 2200 rad for SUVs of 1, 5 and 10, respectively. CONCLUSION: We have shown that positrons delivered by (18)F-FDG to mammary tumors have a tumoricidal effect on cancer cells. The study of breast cancer patients suggests that the tumor and normal organ dosimetry of (18)F-FDG makes it suitable for therapy of this malignancy
AMiBA Wideband Analog Correlator
A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array
for Microwave Background Anisotropy. Lag correlators using analog multipliers
provide large bandwidth and moderate frequency resolution. Broadband IF
distribution, backend signal processing and control are described. Operating
conditions for optimum sensitivity and linearity are discussed. From
observations, a large effective bandwidth of around 10 GHz has been shown to
provide sufficient sensitivity for detecting cosmic microwave background
variations.Comment: 28 pages, 23 figures, ApJ in press
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