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Second Category (second + category)
Selected AbstractsVariation in Vocal Performance in the Songs of a Wood-Warbler: Evidence for the Function of Distinct Singing ModesETHOLOGY, Issue 7 2004Martin D. Beebee Male North American wood-warblers (family Parulidae) subdivide their song repertoires into two different categories, or modes, of singing (first and second category songs). These two modes are thought to be specialized for interacting with females and males, although the data are inconclusive. I conducted an acoustic analysis of the song types used by yellow warblers (Dendroica petechia) for type I (first category) and type II (second category) singing to ask whether there are consistent structural differences between them which could provide insight into how they might function as separate signals. I found that type I songs are performed closer to the upper boundary of a song performance limit, measured in terms of the difficulty of production, compared with type II songs. By contrast, the performance of specific song types did not depend on whether they were used for type I singing vs. type II singing by different males. In addition, type I songs had a greater amplitude increase across the first two syllables compared with type II songs. There was no relationship between the performance of type I or type II songs and male condition. These results suggest that wood-warblers might subdivide their song repertoire into distinct categories to highlight the relative vocal performance of their songs. [source] Saccharomyces cerevisiae plasma membrane nutrient sensors and their role in PKA signalingFEMS YEAST RESEARCH, Issue 2 2010Marta Rubio-Texeira Abstract The ability to elicit a fast intracellular signal leading to an adaptive response is crucial for the survival of microorganisms in response to changing environmental conditions. Therefore, in order to sense changes in nutrient availability, the yeast Saccharomyces cerevisiae has evolved three different classes of nutrient-sensing proteins acting at the plasma membrane: G protein-coupled receptors or classical receptor proteins, which detect the presence of certain nutrients and activate signal transduction in association with a G protein; nontransporting transceptors, i.e. nutrient carrier homologues with only a receptor function, previously called nutrient sensors; and transporting transceptors, i.e. active nutrient carriers that combine the functions of a nutrient transporter and receptor. Here, we provide an updated overview of the proteins involved in sensing nutrients for rapid activation of the protein kinase A pathway, which belong to the first and the third category, and we also provide a comparison with the best-known examples of the second category, the nontransporting transceptors, which control the expression of the regular transporters for the nutrient sensed by these proteins. [source] Mother, Martyr and Mary Magdalene: German Female Pamphleteers and their Self-imagesHISTORY, Issue 291 2003Ulrike Zitzlsperger Female pamphleteers who involved themselves in the German Reformation faced a double challenge: they had to argue why a lay person needed to enter into public debate and, still more controversially, why a woman should brave the consequences of going into print. In this article two noblewomen, Argula von Grumbach and Elisabeth von Braunschweig-Lüneburg, and two middle-class Protestants, Katharina Schütz Zell and Ursula Weida, serve as case studies of how women with noticeably different backgrounds dealt with the challenge. The article focuses on the images they projected of themselves. While some of these images derived from traditional idealized and biblical female figures, others show a creative attempt to argue the case for long-term participation in public debate. The most striking concept within this second category is Katharina Schütz Zell's role as ,Kirchenmutter' (Churchmother). The impact of such an image becomes obvious when Katharina Schütz Zell is compared with the Nuremberg shoemaker-poet, Hans Sachs. An equally outspoken lay participant of the Reformation, his mounting disappointment with religious politics and the decline of his home town led him to withdraw into privacy. In contrast, Katharina Schütz Zell, whose remit was the more closely defined Strasbourg parish, remained actively involved until her death. [source] Effects of juvenile hormone I, precocene I and precocene II on the progeny of Microplitis rufiventris Kok. female when administered via its host, Spodoptera littoralis (Boisd.)JOURNAL OF APPLIED ENTOMOLOGY, Issue 1 2004W. E. Khafagi Abstract: Reproductive biologies of Microplitis rufiventris Kok. females resulting from topically treated Spodoptera littoralis (Boisd.) larvae with constant effective doses of juvenile hormone I (JHI, 1 ,g), precocene I (PI, 25 ,g) or PII (25 ,g) were investigated. Although the female wasps were treated during their presence as eggs or larvae in their hosts, the complete effects of the test compound were not apparent until the wasps had become adults. On the bases of the obtained results, the reproductive inhibition activity caused by the test compounds comprises of two categories: (1) reduction in progeny production, and (2) induction of significant proportion of imperfect ,non-functional' parasitoid progeny. Whereas, the adverse effect of JHI is only restricted to the second category, the adverse effects of PI or PII fall into both categories. Thus, workers should be aware of the delayed effects of new generations of pesticides which may occur in later stages of the non-target insects. [source] Adult-derived stem cells and their potential for use in tissue repair and molecular medicineJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2005Henry E. Young Abstract This report reviews three categories of precursor cells present within adults. The first category of precursor cell, the epiblast-like stem cell, has the potential of forming cells from all three embryonic germ layer lineages, e.g., ectoderm, mesoderm, and endoderm. The second category of precursor cell, the germ layer lineage stem cell, consists of three separate cells. Each of the three cells is committed to form cells limited to a specific embryonic germ layer lineage. Thus the second category consists of germ layer lineage ectodermal stem cells, germ layer lineage mesodermal stem cells, and germ layer lineage endodermal stem cells. The third category of precursor cells, progenitor cells, contains a multitude of cells. These cells are committed to form specific cell and tissue types and are the immediate precursors to the differentiated cells and tissues of the adult. The three categories of precursor cells can be readily isolated from adult tissues. They can be distinguished from each other based on their size, growth in cell culture, expressed genes, cell surface markers, and potential for differentiation. This report also discusses new findings. These findings include the karyotypic analysis of germ layer lineage stem cells; the appearance of dopaminergic neurons after implantation of naive adult pluripotent stem cells into a 6-hydroxydopamine-lesioned Parkinson's model; and the use of adult stem cells as transport mechanisms for exogenous genetic material. We conclude by discussing the potential roles of adult-derived precursor cells as building blocks for tissue repair and as delivery vehicles for molecular medicine. [source] | ||||||||||