Response characteristics of cold cell on the antenna ofLocusta migratoria L.

Summary The dendritic outer segment of the cell which is most likely the cold unit in the poreless coeloconic sensilla onLocusta migratoria antennae, has finger-like projections up to 1.5 m long and 0.13 m thick (Fig. 1). This unit responds to constant temperature, to slowly changing temperature and to step changes. Under stationary conditions impulse frequency attained 35 imp/s. Between 14 °C and 41 °C the higher frequencies were associated with the higher temperatures (Fig. 5). In this range the differential sensitivity is positive but not large: + 0.8 (imp/s)/°C. Its resolving power for steady temperature is 4.7 °C.Downward step changes produced by shifting between airstreams at different temperatures yield far higher frequencies (Figs. 2, 3). Step amplitudes were between –0.1 °C and –12 °C; the conditioning temperature from which the steps were initiated, was between 16 °C and 33 °C. Frequency peaked during the first 50 ms after stimulus onset (Fig. 2) and reached its highest values (310–340 imp/s) at initial temperatures above 30 °C and steps larger than –10 °C (Fig. 4). The mean differential sensitivity from 23 curves was –19 (imp/s)/°C and the resolving power 0.6 °C.During slowly changing temperature the impulse frequency was governed by two parameters simultaneously: ambient temperature and its rate of change. Rates were between 0.001 °C/s or less, and 0.03 °C/s in either direction. Frequency was higher during slow cooling at a given temperature than during slow warming (Fig. 6). The average differential sensitivity to the rate of change was –210 (imp/s)/(°C/s). Further, the larger responses to cooling developed at lower ambient temperatures (differential sensitivity: –1.0 (imp/s)/°C). It is to be noted that this sign is negative, in contrast to the sign for differential sensitivity to constant temperature and also for the influence of initial temperature on the response to downward step changes.Abbreviations b Slope of characteristic curve, differential sensitivity - F impulse frequency in imp/s - imp/s impulses/s - P _w partial pressure of water vapor in torr - r correlation coefficient - T temperature in °C - T T-step - x resolving power in °C     

Chromatographic resolution, characterisation and quantification of VX enantiomers in hemolysed swine blood samples

The present study was initiated to develop a sensitive and highly selective method for the analysis of the enantiomers of the nerve agent VX (O-ethyl S-[2(diisopropylamino)ethyl] methylphosphonothioate) in blood samples for toxicokinetic and therapeutic research. To achieve this goal, analytical and semi-preparative enantioseparation of VX were carried out with gas and liquid chromatography. The GC chiral stationary phase was HYDRODEX-beta-TBDAc (beta cyclodextrin), on which VX was baseline-resolved. On the chiral HPLC phase CHIRALCEL OD-H the enantiomers of VX were isolated with enantiomeric excess >99.99%. They were characterised by specific optical rotation (+/-25.8degmldm(-1)g(-1) at 20 degrees C and 589nm) and by determination of cholinesterase inhibition rate constants. For the quantitative chiral detection of VX the enantioresolution was realized on the HPLC chiral phase CHIRAL AGP. A specific procedure was developed to isolate VX from swine blood samples thereby stabilising its enantiomers. The limit of detection was 200fg per enantiomer on column. The absolute recovery of the overall sample preparation procedure was 75%. After an intravenous and percutaneous administration of a supralethal dose of VX in anesthetised swine (+)-VX and (-)-VX could be quantified up to 720min.     

A revision of Plasmopara penniseti, with implications for the host range of the downy mildews with pyriform haustoria

Plasmopara penniseti is the sole member of the genus Plasmopara parasitic to Poaceae, after the genus Viennotia had been described to accommodate Plasmopara oplismeni. Morphological, ultrastructural, and molecular phylogenetic data indicate that Plasmopara penniseti is not closely related to the generic type, and it is, therefore, transferred to the newly described genus Poakatesthia. The view that the genera of downy mildews with pyriform to vesicular haustoria (Basidiophora, Benua, Bremia, Paraperonospora, Plasmopara, Plasmoverna, and Protobremia) include species parasitic to Poaceae has to be discarded. All of these genera are apparently restricted to dicotyledonous hosts.     

Zur Flora der Umgebung von Görz

Ohne Zusammenfassung     

Biogas Production from Steam-Exploded Miscanthus and Utilization of Biogas Energy and CO2 in Greenhouses

The costs of producing protected vegetables comprise up to 78 % of the total operating costs in greenhouses. These expenses mainly result from energy consumption. Increasing energy efficiency and expanding the use of renewable energy sources are essential for global competitiveness. The aim of this study is to optimize methane production from miscanthus and to evaluate the potential use of miscanthus as a source of electrical energy, heat, and CO₂ in vegetable greenhouses. To optimize methane yield, miscanthus was pretreated by steam explosion using different time/temperature combinations. Pretreatment resulted in a more than threefold increase of methane yield from anaerobic digestion (374 l_N?kgVS^?1) compared with untreated miscanthus. Based on technical parameters from two greenhouses (in Northern and Southern Europe), four different energy balances were established. The balances showed that using methane produced by pretreated miscanthus in vegetable greenhouses can enhance the entire process and therefore make it more sustainable.     

Surface Plasmon Polariton Mach–Zehnder Interferometer and Oscillation Fringes

We present a quantitative experimental analysis of a surface plasmon polariton (SPP) interferometer relying on elliptical Bragg mirrors. By using a leakage radiation microscope, we observe oscillation fringes with unit visibility at the two interferometer exits. We study the properties of the SPP beam splitter and determine experimentally both the norm and phase of the SPP reflection and transmission coefficients.     

Cytokeratins and cytokeratin filaments in subpopulations of cultured human and rodent cells of nonepithelial origin: modes and patterns of formation

Using immunofluorescence microscopy, we observed that in several established cell culture lines derived from different nonepithelial tissues and species, cells spontaneously emerge, usually at low frequencies, which contain cytoplasmic structures decorated by antibodies specific for cytokeratins 8 and 18. This phenomenon was further examined at both the protein (gel electrophoreses of cytoskeletal proteins, followed by immunoblotting) and the RNA (Northern blots, "nuclear run-on" analysis, in situ hybridization) level. Positive cell lines included simian virus (SV40)-transformed human fibroblasts (HF-SV80, WI-38 VA13), human astrocytic glioma cells (U333 CG/343MG), rat (RVF-SMC) and hamster (BHK-21/13) cells derived from vascular smooth muscle and murine sarcoma MS-180 cells. In two cell lines (HF-SV80 and BHK-21/13), the frequency of the cytokeratin-containing cells and of the cytokeratin fibril arrays per cell was drastically increased upon treatment with 5-azacytidine. The structural appearance of the cytokeratins was variable in the different cell lines but could also differ among cells of the same culture: While small granular or comma-shaped structures or bizarrely shaped filament arrays prevailed in WI-38, RVF and normally grown BHK-21 cells, most of the other lines revealed extended normal-looking, fibrillar arrays. In one line (MS-180), the appearance of cytokeratins was associated with a morphological change, as it was only found in a subpopulation of cells that had lost their typical elongated and spindle-shaped phenotype and assumed a rounded ("coccoid") shape. Our results show that the expression of the genes encoding cytokeratins 8 and 18 is not necessarily restricted to programs of epithelial differentiation and that factors stochastically effective appear in cultured cell lines that allow the synthesis of these cytoskeletal components. Mechanisms possibly involved in this spontaneous and selective advent of cytokeratins 8 and 18 and implications for tumor diagnosis are discussed.     

Differential protein expression in anatomical zones of the prostate

The prostate has three anatomical zones: the peripheral (PZ), the transition (TZ), and the central (CZ) zone. It is proposed that the CZ may be of mesodermal origin, whereas the other two are of endodermal origin. Proteome patterns in the zones were characterized to test for differences. Cells were scraped from macroscopically normal areas of PZ, TZ, and CZ in radical prostatectomy specimens. After exclusion of samples with cancer or prostatic intraepithelial neoplasia, 18 cases remained for analysis. Cells were collected in a medium with protease inhibitors, and the protein material was prepared for two-dimensional gel electrophoresis. The proteins in spots that differed quantitatively between regions were identified via mass spectrometric fingerprinting of tryptic fragments and selected tandem mass spectrometry sequence analysis. Ten proteins with significant zonal differential expression were identified, eight with underexpression in the CZ versus the PZ and the TZ (arginase II, ATP synthase, cytokeratin 8, lamin A/C, peroxiredoxin 4, protein disulfide isomerase A3, tropomyosin, and vimentin), and two with overexpression in the CZ (peroxiredoxin 2 and creatine kinase B). The PZ and TZ, although differing in terms of incidence of cancer and hyperplasia, have epithelium with highly similar major protein expression profiles. However, the protein profile of the CZ differs from that of the other regions, suggesting functional differences.