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Real Alternative (real + alternative)
Selected AbstractsPolybenzimidazole-Based Membranes as a Real Alternative to Nafion for Fuel Cells Operating at Low Temperature,ADVANCED MATERIALS, Issue 7 2008Piercarlo Mustarelli Filler up! Composite proton-conducting membranes, based on polybenzimidazole (PBI) and imidazole-derivatized silica are presented. The addition of even small amounts (,10 wt %) of filler causes an outstanding improvement in the permanent proton conductivity by a factor <103. The preparation of PBI composite membranes with basic functionalities is a promising way to make possible their use in PEMFCs operating around 120,°C, that is, the temperature required for automotive applications. [source] Kant on Recognizing BeautyEUROPEAN JOURNAL OF PHILOSOPHY, Issue 3 2010Katalin Makkai This essay takes up the question of what this might mean and whether it can be taken seriously. It is often supposed that Kant's denials of ,objectivity' to the judgment of beauty express a rejection of realism about beauty. I suggest that Kant's thought is not to be understood in these terms,that it does not properly belong in the arena of debates about the constituents of ,reality',motivating the suggestion by first considering a pair of opposing views on the question of whether Kant can be understood to develop a real alternative to realism about beauty at all. [source] The Marriage of Marx and Darwin?HISTORY AND THEORY, Issue 1 2002Doyne Dawson Recent attempts to develop scientific research strategies for cultural evolution have mostly drawn upon evolutionary biology, but within anthropology there is also an influential tradition of non-biological evolutionary thought whose basic principle is adaptation to the environment. This article is mainly concerned with the "cultural materialist" school of Marvin Harris, but also treats the recent attempt of Jared Diamond to create a more radical model of evolutionary ecology. I argue that the ecological tradition does not represent a real alternative to neo-Darwinism and is in fact a pseudo-Darwinist theory. I also suggest that the bias in favor of materialistic explanation in cultural evolution may not be justified. [source] Generation of a scaffold free cartilage-like implant from a small amount of starting materialJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 2 2006M. J. Stoddart Abstract Introduction: An autologous cellular based treatment of a traumatic cartilage injury requires a procedure whereby a biopsy of healthy cartilage is removed from the patient and the cells isolated and expanded by monolayer passage. This increases the cell number to required levels but also leads to a de-differentiation of the cells. We aim to produce a scaffold-free, de-novo implant from a biopsy of cartilage. Methods: Bovine chondrocytes were isolated from a small biopsy and expanded. The chondrocytic phenotype of the monolayer expanded cells was recovered during a period of culture in alginate and the effect of factors such as IGF1, TFG,1 and dexamethasone was investigated. Results: During the alginate culture period a pre-treatment with IGF1 and dexamethasone was shown to have little effect. IGF1 however increased the glycosaminoglycan/DNA (GAG/DNA) content on day 14 to 84.95±5ng/ng compared with 37.3±1.8ng/ng in the controls (P <0.001). 35S labeling demonstrated an increased GAG synthesis in the presence of IGF1 (P < 0.001). IGF1 also induced a increase of DNA content 1383±314ng/bead compared to 512±19ng/bead in the controls (P < 0.001). The cells were released from the alginate and cultured in a silicon mould for a further 14 days to obtain a three dimensional implant. Releasing the cells from the alginate and casting in a mould produced an implant of defined shape which contained no foreign material. After 31 days of culture the implants contained 152.4±13.14ng/ng GAG/DNA and 42.93±10.23ng/ng collagen II. Discussion: We believe alginate released chondrocytes provide a real alternative to artificial scaffolds. [source] COALESCENCE VERSUS COMPETITION: FIELD AND LABORATORY STUDIES OF INTRA- AND INTERSPECIFIC ENCOUNTERS AMONG COALESCING SEAWEEDSJOURNAL OF PHYCOLOGY, Issue 2000B. Santelices Classical ecological theory predicts that whenever growing individuals share a common and limiting resource, such as substratum in mid-intertidal and shallow subtidal habitats, preemptive competition will occur determining species abundance and distribution patterns. However, conspecificity of several ecologically dominant Rhodophyta may coalesce when grown in laboratory cultures. The extent at which intraspecific coalescence occurs in the field and whether the process may also happens during interspecific encounters remain to be determined. If intra- and interspecific coalescence effectively occurs, then coexistence through coalescence rises as an alternative to competition among red-algal dominated intertidal and shallow subtidal communities. Populations of Mazzaella laminarioides and Nothogenia fastigiata living in mid-intertidal, semi-exposed rocky habitats in Central Chile are being used to test the above ideas. Intra- and interspecific encounters occur in the field throughout the year. Coalescence does occur among conspecific partners but it has not been detected in interspecific encounters. Rather, a thick interface of compressed cells, necrotic tissues and cyanobacterial nodules is formed between the two contacting partners. In addition, observations of laboratory cultures indicate that spore germination, germling survival and differentiation of erect axes in bispecific cultures may be reduced when compared to single-species controls. Interspecific differences in growth and differentiation rates appear as the mechanisms explaining a lack of coalescence and negative effects during interspecific contacts. On the other hand, the existence of conspecific coalescence in the field suggests this process should be considered as a real alternative to intraspecific competition among coalescing Rhodophyta. [source] | ||||||||||