Cytochemical characteristics of the golgi apparatus

Lectinocytochemistry provides a useful tool for localizing subcompartments of the complex reticular apparatus of Golgi. The technique is based on interactions of lectins with glycoconjugates present in the limiting membranes and luminal spaces of Golgi elements. Application of a series of lectins of different sugar specificities permits a differentiation between Golgi subcompartments containing glycoconjugates with different oligosaccharide side chains. These may be (a) different glycoconjugates or (b) glycoconjugates at different stages during synthesis or repair of their glycans. The lectinocytochemical studies with mannose-, glucose-, N-acetyl-glucosamine-, N-acetylgalactosamine-, galactose-, fucose-, and sialic acid-recognizing lectins revealed predominating patterns that labeled distinct, i.e., cis, medial, trans, and transmost, regions of the Golgi apparatus. A further refinement could be achieved by differential lectin-inhibition that enables a dissection of lectin binding reactions on the basis of their binding affinities. High-affinity binding reactions showed that subcompartments are not necessarily confined to one single Golgi subregion and may change their position from one to another subregion. Some of the patterns observed may be interpreted in relation to certain steps during synthesis and modifications of glycans.     

Online world modeling and path planning for an unmanned helicopter

Mission scenarios beyond line of sight or with limited ground control station access require capabilities for autonomous safe navigation and necessitate a continuous extension of existing and potentially outdated information about obstacles. The presented approach is a novel synthesis of techniques for 3D environment perception and global path planning. A locally bounded sensor fusion approach is used to extract sparse obstacles for global incremental path planning in an anytime fashion. During the flight, a stereo camera checks the field of view along the flight path ahead by analyzing depth images. A 3D occupancy grid is built incrementally. To reduce the high data rate and storage demands of grid-type maps, an approximated polygonal world model is created. For a compacted representation, it uses prisms and ground planes. This enables the system to constantly renew and update its knowledge about obstacles. An incremental heuristic path planner uses both a-priori information as well as incremental obstacle updates to assure a collision-free path at any time. Mapping results from flight tests show the functionality of onboard world modeling from real sensor data. Path planning feasibility is demonstrated within a simulation environment considering world model changes inside the vehicle’s field of view.     

Anharmonic frequency analysis: the complement to Fourier analysis

Fourier analysis of a finite time series allocates amplitudes and phases to a given set of frequencies which are integer multiples of a basic frequency determined by the length of the time series. Anharmonic frequency analysis (Afa)collects the spectral components between those frequencies and the results are the average amplitude and phase for each band defined by two consecutive frequencies. A repetition of the transform involved for a later reference time determines the effective frequency within each band by the time change of the phase. This process is by far superior to Fourier analysis especially if unknown discrete frequencies are present in the time series and those frequencies are not harmonics of one common basic frequency. The principles of this method, some of its properties and a few results are presented.     

A novel facile synthesis and characterization of molybdenum nanowires

We describe a straightforward technique to synthesize pure Mo nanowires (NWs) from Mo₆S_yI_z (8,2 <y + z ≤ 10) NWs as precursor templates. The structural transformations occur when Mo₆S_yI_z NWs are annealed in Ar/H₂ mixture leading to the formation of pure Mo NWs with similar structures as initial morphologies. Detailed microscopic characterizations show that large diameters (>15 nm) Mo NWs are highly porous, while small diameters (<7 nm) are made of solid nanocrystalline grains. We find NW of diameter 4 nm can carry up to 30 μA current without suffering structural degradation. Moreover, NWs can be elastically deformed over several cycles without signs of plastic deformation.     

The yeast growth control gene GRC5 is highly homologous to the mammalian putative tumor suppressor gene QM

We isolated the Saccharomyces cerevisiae GRC5 (gr owth control) gene by functional complementation in vivo of a ts (t emperature s ensitive) mutation. Phenotypic analysis suggested involvement of GRC5 in cell growth and proliferation. Mutant cells arrest their cell cycles after one to three cell divisions predominantly as mother cells with a large bud. In the region of the septum, a massive accumulation of cell wall material is observed. The mother and daughter nuclei are well separated and spindles are no longer present, while the cytoskeleton is of aberrant appearance. Arrested cells do not perform protein synthesis and are unable to mate. Furthermore, grc5-1^ts cells rapidly lose viability at the restrictive temperature (37°C) only on full media, but not under nitrogen-starvation conditions, indicating that proper response to this nutrient limitation is still intact in mutant cells after cell cycle arrest. The sequence of GRC5 translates into a basic protein of 221 amino acids with a corresponding M_r of 25·4 kDa. GRC5 is a member of the highly conserved QM gene family, members of which have been reported from plants, invertebrates and vertebrates. The amino acid sequence of GRC5 over its entire length is more than 60% identical to the human QM protein, expression of which is associated with loss of the tumorigenic phenotype in a cell line derived from Wilms' tumor, a malignancy of the embyronic kidney. Here, we show that GRC5 is an essential yeast gene, the function of which as inferred from analysis of the grc5-1^ts mutant is crucial for establishment of proper cytoskeletal structure and regulation of growth in yeast cells.     

Is Sigmund Freud's psychoanalytic edifice relevant to the 21st century?

[Correction Notice: An erratum for this article was reported in Vol 24(3) of Psychoanalytic Psychology (see record 2007-10890-003). The article contains two distorting misprints: (1) On p. 257, in the footnote, the title of the author's academic chair should read: Andrew Mellon Professor of Philosophy of Science; (2) On p. 274, line 2, in the quotation from Marshall Edelson on "Transference Phenomena," the word "on" just before "question-begging evidence" should read negatively as "non."] To warrant the relevance, if any, of Freud's psychoanalytic edifice to the 21st century, its supporters must endeavor, if at all possible, to find genuine evidence for its major pillars or to modify them significantly in response to emerging new evidence. Such a quest must begin with a clear understanding of the range and depth of the failure of Freud's cardinal clinical arguments. I endeavor below to provide such comprehension by laying bare the epistemological gravamen in the case of each of his principal tenets. And I argue that neither the post-Freudian formulations of psychoanalysis nor its so-called "hermeneutic" reconstruction has succeeded in vindicating the psychoanalytic enterprise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anwendung des quantitativen Fernsehmikroskopes und der Elektronenstrahlmikrosonde für die Untersuchung des Systems Eisen—Kohlenstoff—Phosphor bei 900 bis 1000°C

Neue Wege, mit geringem Aufwand an Legierungen metallische Mehrstoffsysteme im festen Zustand zu untersuchen: 1. durch Mengenmessung der Phasen mit dem quantitativen Fernsehmikroskop und Errechnung der Sättigungskonzentrationen, 2. durch Ermittlung der Phasenzusammensetzung mit der Elektronenstrahlmikrosonde. Vergleich der herkömmlichen und neuen Verfahren. Untersuchung der Eisenecke des Systems Eisen–Phosphor–Kohlenstoff bei 900, 950 und 1000°C.