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Annette Schäfer, Zwangsarbeiter und NS-Rassenpolitik. Russische und polnische Arbeitskräfte in Württemberg 1939-1945 (Veröffentlichungen der Kommission für geschichtliche Landeskunde in Baden-Württemberg. Reihe B: Forschungen, Bd. 143), Stuttgart (W. Kohlhammer) 2000. 289 S.

Newly planted hedges as refuges for aphids and their predators. A contribution to the Lautenbach-project In the area of Lautenbach-farm near Heilbronn three field-hedges were planted with respect to the needs of integrated pest control. From these hedges samples were taken by means of the Steiner-funnel. The insects were classified as phytophagous, entomophagous or indifferent regarding their food. The phytophagous insects were concentrated on certain plants, as Rosa canina, Lonicera xylosteum and Crataegus monogyna, whereas the distribution of the entomophagous insects was more homogeneous. However, the linkage of the specialized predators to their prey was evident. The plant most inhabited by insects was Rosa canina. Zusammenfassung Von drei neugepflanzten Feldhecken wurden in den Jahren 1981 und 1982 Proben mit dem Klopftrichter nach Steiner genommen. Die Fange wurden nach der Ernahrungsweise in phytophage, entomophage und indifferente Insekten eingeteilt. Alle Gruppen zeigen im Jahresverlauf eine zweiphasige Entwicklung. Dabei sind die Schwankungen innerhalb der phytophagen am grosten. Die entomophagen zeigen eine regelmasigere Verteilung auf einzelne Pflanzenarten als die phytophagen, doch last sich die Bindung an ihre Beutetiere immer erkennen. Von den einzelnen Pflanzenarten wird Rosa offenbar bevorzugt besiedelt.

The post mortem changes in water mobility and distribution were followed in porcine muscle ( M. longissimus dorsi ) samples using continuous low-field NMR relaxation measurements and simultaneous measurement of changes in muscle impedance as an indirect measure of membrane integrity as well as muscle contraction measurements using a rigormeter instrument. Distributed exponential fitting analysis of NMR T 2 relaxation data revealed the presence of three distinct water populations ( T 20 , T 21 , T 22 ) within the muscle during its conversion to meat. Comparison of T 2 relaxation patterns and contraction data indicates that rigor development affects the attributes of the T 21 water population and thereby contributes to myofibrillar water characteristics post mortem, as the T 21 water population is believed to reflect inter/intra-myofibrillar water. The volume of the water population believed to reflect extra-cellular water ( T 22 ) in the living muscle. Early post mortem T 22 decreased slightly within the first 2–3 h post mortem followed by an increase and a change in its characteristic time constant. This was ascribed to an initial muscle cell swelling followed by water being expelled from the cellular space into the extra-myofibrillar space. Comparison of changes in the T 22 water population and impedance characteristics within the muscle during its conversion to meat revealed close relationship between progresses in the two attributes. Obtained data strongly support that the post mortem reorganization of water is closely associated with membrane properties, which moreover was found to affect the final water-holding capacity of the meat. Finally, a model for early post mortem events leading to changes in the distribution of water within muscles is proposed.

ARVCF, a member of the catenin family, is thought to contribute to the morphoregulatory function of the cadherin-catenin complex. Recently, we reported the isolation and characterisation of murine ARVCF (mARVCF), particularly its interaction with M-cadherin. Here, we describe the identification of novel mARVCF isoforms that arise by alternative splicing. At the N-terminus, alternative splicing results in the inclusion or omission of a coiled-coil region probably important for protein-protein interactions. At the C-terminus, four isoforms also differ by domains potentially important for selective protein-protein interaction. The eight putative mARVCF isoforms were expressed as EGFP-fusion proteins in six different cell lines that exhibit a distinct pattern of cadherins. Apparently, binding of the mARVCF isoforms to M-, N-, or E-cadherin is generally unaffected by their altered N- and C-termini, as revealed by the MOM recruitment assay. However, mARVCF isoforms reproducibly exhibit differential localisation in distinct cellular environments. For example, mARVCF isoforms are unable to colocalise with N-cadherin in EJ28 carcinoma cells but do so in HeLa cells. Our results suggest that the subcellular localisation of mARVCF may be determined not only by the presence or absence of an appropriate interaction partner, in this case cadherins, but also by the cellular context.

Biological air filters have been proposed as a cost-effective technology for reducing odor emissions from intensive swine production facilities. In this work we present results from the application of membrane inlet mass spectrometry (MIMS) for continuously monitoring the removal of odorous compounds in biological air filters. The sensitivity and selectivity were tested on synthetic samples of selected odorous compounds, and linearity and detection limits in the lower ppb range were demonstrated for all compounds tested (methanethiol, dimethyl sulfide, carboxylic acids, 4-methylphenol, aldehydes, indole, and skarole) except trimethylamine. The method was applied in situ at two full-scale filters installed at swine houses. The results have been compared with analyses by thermal desorption gas chromatography-mass spectrometry (TD-GC/ MS), and odor was measured by olfactometry. By comparison with TD-GC/MS, observed MIMS signals were assigned to 4-methylphenol, 4-ethylphenol, indole, skatole, the sum of volatile reduced organic sulfur compounds (ROS), and three subgroups of carboxylic acids. The removal rates were observed to be related to air―warer partitioning with removal efficiencies in the range of 0 to 50% for low-soluble organic sulfur compounds and high removal efficiencies (typically 80―100%) for more soluble phenols and carboxylic acids. Based on the results and published odor threshold values, it is estimated that the low removal efficiency of ROS is the main limitation for achieving a higher odor reduction.

Single odorants in the outlet air from swine units have been measured by sampling air on adsorption tubes followed by analysis by GC-MS (Gas Chromatography - Mass Spectrometry). Additionally, online measurements by MIMS (Membrane Inlet Mass Spectrometry) have been carried out to record variation in odorant concentrations over time. Two different chemical treatments for reducing odor from growing-finishing swine units have been tested in practice. In the first set-up, the slurry was taken out from the swine unit once a week and was treated with ozone to oxidize odorous metabolites formed during the fermentation process and to control the production of these metabolites by odor-causing microorganisms. After treatment, an almost clear and odorless liquid fraction was pumped back into the swine unit. In the second set-up, a two-step chemical air scrubber that washed the outlet air with water and sulfuric acid, respectively, was used. All treatments were carried out as case-control studies. For the ozone treatment, two identical swine units were used with a unit without any treatment of the slurry as control. For the air scrubber, measurements were taken before and after purification of the air. After the slurry had been treated with ozone, decreases in sulfides, phenols, and volatile fatty acids (VFA) in the outlet air ranging from 25 to 100% were observed. Skatole, indole and metabolites, such as aldehydes and ketones, showed a more complex pattern. The air scrubber had a significant effect on volatile fatty acids, whereas only a modest effect on hydrophobic odorants was observed.

The effect of glucose, glucose 6-phosphate, mannose and ribose on the generation of aroma volatiles in pork was investigated. The monosaccharides were added individually to minced pork prior to heat treatment (160 °C for 10 min) in the following concentrations: glucose (27.5 μmol/g), ribose (1.2 μmol/g), mannose (8.3 μmol/g) and glucose 6-phosphate (0.5 μmol/g). The natural concentrations of the monosaccharides in the pork used were found to be 4.0 μmol/g for glucose, 0.1 μmol/g for ribose, 0.3 μmol/g for mannose and 2.6 μmol/g for glucose 6-phosphate. The major aroma compounds identified in the headspace of the heated samples were pyrazines, aldehydes (Strecker and lipid-derived), ketones, and sulphides. Glucose generated the highest amounts of volatiles followed by glucose 6-phosphate. However, when related to the added concentration of glucose 6-phosphate, this phosphorylated monosaccharide showed the highest aroma generating potential. The addition of ribose did not increase the concentration of volatiles compared with pork without the added monosaccharide. The fates of ribose 5-phosphate and ribose in pork were studied over time. The concentrations of ribose and ribose 5-phosphate clearly decreased during 2 h equilibration, which may be due to enzymatic activities. These precursors may, therefore, be less important pork flavour precursors than glucose and glucose 6-phosphate.

Six fatty acids (C18:1(9), C18:2(9,12), C18:3(9,12,15), C18:3(6,12,15), C20:4(5,8,11,14) and C22:6(4,7,10,13,16,19)) were added separately to minced pork, which was subsequently heat-treated. The odour of the samples was assessed by a sensory panel. Especially the addition of the omega-3-fatty acids, C18:3(9,12,15) and C22:6(4,7,10,13,16,19), resulted in a fish-like odour, whereas the addition of C18:2(9,12) resulted in an oily odour. Three meat samples with fatty acids, C18:2(9,12), C18:3(9,12,15) or 22:6(4,7,10,13,16,19), were further analysed by gas chromatography-olfactometry-mass spectrometry, GCO-MS, using 8 assessors. The differences in odour active compounds between the three fatty acid additions were small.

Candida albicans forms unconstricted hyphae in serum-containing medium that are divided into discrete compartments. Time-lapse photomicroscopy, flow cytometry, and a novel three-dimensional imaging system were used to demonstrate that the kinetics and cell cycle events accompanying hyphal development were correlated with dynamic changes in vacuole morphology and the pattern of vacuole inheritance. Apical cells of hyphae underwent continuous extension before and after the first cytokinesis event. However, the resulting mother cell and sub-apical compartments did not immediately reenter the cell cycle and instead underwent cell cycle arrest before reentering the cycle. Vacuole was inherited asymmetrically at cytokinesis so that the distal, arrested compartments inherited most vacuole and the growing apical cell inherited most cytoplasm. Hydroxyurea release experiments demonstrated that the arrested, vacuolated hyphal compartments were in the G 1 phase of the cycle. The period of cell cycle arrest was decreased by the provision of assimilatable forms of nitrogen, suggesting that the hyphal cell cycle is regulated by nitrogen limitation that results in sup-apical cell cycle arrest. This pattern of growth is distinct from that of the synchronous, symmetrical development of pseudohyphae of C. albicans and other yeast species. These observations suggest that the cellular vacuole space correlates with alterations in the cell cycles of different cell types and that the total organelle space may influence size-regulated functions and hence the timing of the eukaryotic cell cycle.

Early post mortem metabolism and structural changes from 3 to 24 h, together with pH, temperature and impedance Py development were investigated in 37 Duroc×Landrace×Large White (DLY) pigs covering a range of drip loss from 2.2 to 12.6%. Multivariate statistical analysis was used to assess the impacts of different metabolites, pH and temperature, impedance, cytoskeletal protein degradation and extracellular cross-sectional area on drip loss. Taken as single factors, the concentration of lactate could explain 80% of the variation in drip, inosine monophosphate (IMP) and adenosine triphosphate (ATP) concentration explained 71 and 68%, respectively, whereas inosin and glycogen levels explained only 59 and 60%. The extracellular area was found to explain 39% of the variation in drip. The area between fibres provided more significant information than did the area between fibre bundles. The degradation of the cytoskeletal proteins was not related to drip loss. Impedance Py development over 24 h could explain 66% of the variation in drip, whereas pH and temperature explained 85 and 87%, respectively. A model including all measured variables could explain 83% of the variation in drip. However, only pH, temperature, impedance, [ATP](1 h) and [lactate](1 h and 2 h) were significant in relation to drip. By reducing the variables in the multivariate analysis, 89% of the variation in drip could be explained by a model containing only pH(2 h) and temperature(1 min). To explain variation in drip loss, pH and temperature measurements at significant time points were sufficient. Variation in post-mortem metabolites did, however, explain why variation in pH and temperature occurred. Development of drip channels was ruled by pH and temperature while impedance development was highly correlated to pH. This multi-faceted study shows those parameters, which can best be used to indicate or predict WHC, as well as those indicating the basic mechanism underlying variations in drip.

Rapid progress in the functional analysis of germline segregation has been made recently using the mouse as an experimental and molecular model. However, comparative vertebrate embryology suggests that the time point and mode of germline segregation may vary between mammalian species to a greater extent than hitherto suspected. Therefore, we started to make use of the monoclonal antibody PG-2 specific for primordial germ cells (PGCs) of the rabbit as an opportunity to investigate the early phases of germ cell formation in a mammalian species other than the mouse. Using immunohistochemistry on whole mount preparations and frozen sections we describe the typical mitochondrial labelling of PGCs in the posterior part of the primitive streak at 7.0 days post conception (d.p.c.) and the subsequent distribution of labelled PGCs at early somite stages (8 d.p.c.) within a bilobed area that flanks the posterior margin of the embryo. At these later stages, PGCs were found close to, and within, the yolk sac epithelium but they were still within the confines of the embryo as defined by the peripheral margin in the epiblast/ectoderm layer. Interestingly, cells expressing the PG-2 epitope in an atypical, finely granulated intracellular pattern were found in the hypoblast layer, but not in the epiblast, at the primitive streak stage. This atypical expression pattern may be interpreted as a sign of cells gradually losing the PG-2 epitope and this, in turn, may indicate that PGC progenitors are allocated to the hypoblast layer before appearing in the mesoderm compartment of the primitive streak. These results raise the question as to whether the germline in the rabbit is separated during early blastocyst stages, i.e. rather earlier than in the mouse.

The odour profiles of cooked pork samples with carbohydrates added at four times the estimated natural concentration were investigated. The heated pork samples were analysed by descriptive odour profiling and the aroma volatiles were measured by GCMS. A screening of eleven different flavour precursors, which were mainly carbohydrates, showed that six precursors altered the odour compared to the reference sample without precursor addition. Glucose, glucose 6-phosphate, ribose, ribose 5-phosphate, and fructose increased the caramel and grilled odours, while lactate increased the sour odour. The remaining five precursors did not alter the sensory profile compared to the reference. GC-MS analysis of pork with added glucose, glucose 6-phosphate, and ribose, respectively, showed an increase in the formation of Maillardderived volatiles compared to the reference. Especially samples with added ribose and glucose showed increased levels. Alkylpyrazines were the most abundant class of volatiles identified in the samples.