Home About us Contact
|
Home About us Contact | ||
|
|
||
Crucial Prerequisite (crucial + prerequisite)
Selected AbstractsEPISTEMOLOGICAL CONSIDERATIONS ON NEUROIMAGING , A CRUCIAL PREREQUISITE FOR NEUROETHICSBIOETHICS, Issue 6 2009CHRISTIAN G. HUBER ABSTRACT Purpose: Whereas ethical considerations on imaging techniques and interpretations of neuroimaging results flourish, there is not much work on their preconditions. In this paper, therefore, we discuss epistemological considerations on neuroimaging and their implications for neuroethics. Results: Neuroimaging uses indirect methods to generate data about surrogate parameters for mental processes, and there are many determinants influencing the results, including current hypotheses and the state of knowledge. This leads to an interdependence between hypotheses and data. Additionally, different levels of description are involved, especially when experiments are designed to answer questions pertaining to broad concepts like the self, empathy or moral intentions. Interdisciplinary theoretical frameworks are needed to integrate findings from the life sciences and the humanities and to translate between them. While these epistemological issues are not specific for neuroimaging, there are some reasons why they are of special importance in this context: Due to their inferential proximity, ,neuro-images' seem to be self-evident, suggesting directness of observation and objectivity. This has to be critically discussed to prevent overinterpretation. Additionally, there is a high level of attention to neuroimaging, leading to a high frequency of presentation of neuroimaging data and making the critical examination of their epistemological properties even more pressing. Conclusions: Epistemological considerations are an important prerequisite for neuroethics. The presentation and communication of the results of neuroimaging studies, the potential generation of new phenomena and new ,dysfunctions' through neuroimaging, and the influence on central concepts at the foundations of ethics will be important future topics for this discipline. [source] Sample preparation procedures for biological atomic force microscopyJOURNAL OF MICROSCOPY, Issue 3 2005K. EL KIRAT Summary Since the late 1980s, atomic force microscopy (AFM) has been increasingly used in biological sciences and it is now established as a versatile tool to address the structure, properties and functions of biological specimens. AFM is unique in that it provides three-dimensional images of biological structures, including biomolecules, lipid films, 2D protein crystals and cells, under physiological conditions and with unprecedented resolution. A crucial prerequisite for successful, reliable biological AFM is that the samples need to be well attached to a solid substrate using appropriate, nondestructive methods. In this review, we discuss common techniques for immobilizing biological specimens for AFM studies. [source] The use of Artificial Neural Networks to classify primate vocalizations: a pilot study on black lemursAMERICAN JOURNAL OF PRIMATOLOGY, Issue 4 2010Luca Pozzi Abstract The identification of the vocal repertoire of a species represents a crucial prerequisite for a correct interpretation of animal behavior. Artificial Neural Networks (ANNs) have been widely used in behavioral sciences, and today are considered a valuable classification tool for reducing the level of subjectivity and allowing replicable results across different studies. However, to date, no studies have applied this tool to nonhuman primate vocalizations. Here, we apply for the first time ANNs, to discriminate the vocal repertoire in a primate species, Eulemur macaco macaco. We designed an automatic procedure to extract both spectral and temporal features from signals, and performed a comparative analysis between a supervised Multilayer Perceptron and two statistical approaches commonly used in primatology (Discriminant Function Analysis and Cluster Analysis), in order to explore pros and cons of these methods in bioacoustic classification. Our results show that ANNs were able to recognize all seven vocal categories previously described (92.5,95.6%) and perform better than either statistical analysis (76.1,88.4%). The results show that ANNs can provide an effective and robust method for automatic classification also in primates, suggesting that neural models can represent a valuable tool to contribute to a better understanding of primate vocal communication. The use of neural networks to identify primate vocalizations and the further development of this approach in studying primate communication are discussed. Am. J. Primatol. 72:337,348, 2010. © 2009 Wiley-Liss, Inc. [source] Brothers smell similar: variation in the sex pheromone of male European Beewolves Philanthus triangulum F. (Hymenoptera: Crabronidae) and its implications for inbreeding avoidanceBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2006GUDRUN HERZNER Female choice is thought to increase the fitness returns of females. The complementary choice model states that the best mate depends on the particular genotype of a female. Aculeate Hymenoptera represent a special case of complementary female choice because males should be chosen on the basis of their allele at the sex determination locus. The prevalent sex determination mechanism in bees and wasps (single-locus complementary sex determination) requires that, to produce a daughter, diploid offspring are heterozygous at the sex determination locus. Otherwise, infertile diploid males result. Inevitably, the proportion of diploid males increases with the rate of inbreeding. In the European Beewolf, males scent mark territories to attract mates and the composition of the pheromone might provide a basis for female choice. One crucial prerequisite for females to be able to discriminate against brothers and avoid inbreeding is that the male sex pheromone varies with familial affiliation. This hypothesis was tested by analysing the pheromone of male progeny of eight mothers using gas chromatography and mass spectrometry. A significantly higher similarity was found among brothers than among unrelated individuals. Such a genetic component of a male sex pheromone has not yet been described from aculeate Hymenoptera. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 89, 433,442. [source] | ||||||||||