Yersiniosis is caused by Y. enterocolitica and Y. pseudotuberculosis mostly presenting as intestinal infection. The infection is usually acquired from contaminated food. The aim of this study was to determine the seroprevalence of anti- Yersinia antibodies in Austrians. Sera of 750 healthy Austrians from all nine states were tested for anti- Yersinia IgG antibodies using the recomBlot Yersinia Westernblot ® kit. Overall seroprevalence was 29.7%. Seroprevalence increased significantly with age from 24.7% in the group of the 19 to 24 year olds to 38.5% in the group of persons older than 44 years. The seroprevalence of anti- Yersinia antibodies varied within the states between 18% and 43.5%. The high seroprevalence of anti- Yersinia antibodies in contrast to only approximately 100 reported yersiniosis cases per year points to the fact that the majority of infections is either subclinical or mild.

Anthrax Blood Agar (ABA) and Cereus Ident Agar (CEI) were evaluated as selective growth media for the isolation of Bacillus anthracis using 92 B. anthracis and 132 other Bacillus strains from 30 species. The positive predictive values for the identification of B. anthracis on ABA, CEI, and the combination of both were 72%, 71%, and 90%, respectively. Thus, less than 10% of all species were misidentified using both nutrient media. Species which might be misidentified as B. anthracis were B. cereus, B. mycoides, and B. thuringiensis. Particularly, 30% of B. weihenstephanensis strains were misidentified as B. anthracis.

Little is known about the prevalence of caprine yersiniosis in Germany. Only few cases are reported every year. The intention of the survey was to provide representative data on the seroprevalence of anti-Yersinia antibodies in goats in the German state of Lower Saxony. A commercially available Western blot kit was used to identify caprine and ovine anti-Yersinia antibodies against five proteins [YopM, H, D, E and V-antigen (V-Ag)]. Of the 681 investigated goat sera, 449 (66%) had anti-Yop/V-Ag antibodies. Only two of 28 animal holdings housed sero-negative goats. Boxplot analysis showed that the number of non-reactive animals is correlated to the size of a herd and the fact of milk production, respectively. A tendency was observed that various management factors may influence the anti-Yersinia antibody status. No statement was possible on the impact of keeping additional carrier animals such as pigs, cows or sheep on a farm or the type of husbandry on the seroprevalence of anti-Yersinia antibodies. This study provides trend-setting data for yersiniosis in goat-holdings. The impact on consumer health, i.e. especially for risk groups-like people allergic to cow milk and the impact on the profit of a farm will have to be elucidated in further studies.

Yersiniosis is considered to be an emerging infection in humans. It is believed that contaminated pork is the main source of infection for man but also beef and cow milk might cause infection in the consumer. Therefore, a survey was carried out to obtain actual data on the prevalence of anti-Yersinia antibodies within cattle. 600 serum samples were taken form 120 farms located in 43 districts of Bavaria, Germany. Antibodies were detected in 396 animals (65.7%) revealing a distribution of 52.3% of anti-YopD, 40.3% of anti-YopM, 24.0% of anti-YopH, 21.2% of anti-YopE and 3.0% of anti-V-antigen antibodies. 21 reactionpatterns out of 32 possible patterns were identified. Anti-YopD and YopM antibodies were sufficient to detect all Yersinia antibody positive sera. No regional differences in the distribution of antibodies were noted.

The aim of the present study was to provide current data on the prevalence of anti-Yersinia-antibodies in Bavarian slaughtering pigs. The recomBlot Westernblot assay based on five recombinantly produced Yersinia Outer Proteins (YopD, YopE, YopH, YopM, V-antigen) is well evaluated for the use in the diagnosis of human yersiniosis and proved to be also a valuable tool for the detection of porcine antibodies. 965 out of 1002 meat juice samples collected in 53 Bavarian pig farms contained anti-Yop/V-Ag-antibodies. Only blots with three or more detectable signals were considered as positive. On the basis of these results a possible previous history of Yersinia infection was detected in 45.4% of the pigs and all of the pig farms. The high prevalence of anti-Yersinia-antibodies found in this investigation demonstrates the need for further epidemiological surveillance and animal studies to assess consumers' endangering.

Yersinia (Y.) pseudotuberculosis infections may lead to significant lethality in European brown hare (Lepus europaeus, Pallas) populations especially during the cold and wet seasons. In recent decades, also Y. enterocolitica was isolated from hares found dead. Consequently, a Western-blot technique proved to be valuable for the detection of antibodies against all pathogenic Yersinia isolates was applied to monitor the prevalence of antibodies in hare populations in North-Rhine Westphalia, Germany. A total of 89.6% of the 230 animals tested was seropositive. Further investigations should be performed to elucidate the role of subclinical yersiniosis in the decline of European brown hare populations in Germany.

The ground reaction forces exerted by the legs of freely walking stick insects, Carausius morosus, were recorded during normal and perturbed locomotion. The animals walked along a path into which a three-dimensional force transducer was integrated. The transducer registered all three components of the forces produced by a single leg when, by chance, it walked on the force platform. The stiffness of the walking surface was found to be a critical variable affecting the forces and the trajectories of leg movements during undisturbed walking. The forces produced by a leg were considerably smaller and the trajectories were closer to the body during walking on soft versus stiff surfaces. Perturbations during stance were generated by moving the platform in various directions within the horizontal plane and at two different rates. Perturbations were applied either immediately after leg contact or after a delay of 300 ms. The reactions to these disturbances were compatible with the hypothesis that the velocity of leg movement is under negative feedback control. This interpretation is also supported by comparison with simulations based upon other control schemes. We propose a model circuit that provides a combination of negative and positive feedback control mechanisms to resolve the apparent discrepancies between our results and those of previous studies.

Zusammenfassung: Das Frühsommer-Meningoenzcphalitis-Virus (FSME) wird in Europa überwiegend durch den Stich der Schildzecke Ixodes ricinus übertragen.Die Durchseuchung der Zecken weist regional große Unterschiede auf.In Deutschland gelten besonders das Bodensee-/Oberrheingebiet sowie der Raum Passau (Bayern) als endemisch.Das neurotrope FSME-Virus verursacht ein zweigipfliges Krankheitsbild: einem eher unspezifischen Prodromalstadium folgen nach mehreren beschwerdefreien Tagen Organmanifestationen als Meningitis,

The effects of pH on K+ conductance were measured using the amphotericin perforated-patch whole cell voltage-clamp technique in freshly dispersed rabbit corneal epithelial cells. Bath perfusion with pH 6.00 Ringer solution after standard Ringer solution (pH 7.35) increased outward K+-selective current (I(K)) from 120 +/- 29 to 312 +/- 64 pA during a step depolarization to +50 mV and hyperpolarized the resting membrane potential (Em) from -52 +/- 5 to -62 +/- 3 mV (n = 15, P < or = 0.05). Increasing bath pH to 8.5 decreased I(K) from 183 +/- 40 to 114 +/- 35 pA (n = 6, P < or = 0.05) and depolarized Em from -63 +/- 6 to -53 +/- 5 mV (n = 6, P < or = 0.05). Intracellular acidification using the weak electrolyte (NH4)2SO4 also increased I(K) from 83 +/- 15 to 183 +/- 20 pA (n = 4, P = 0.01) and hyperpolarized Em from -51 +/- 8 to -68 +/- 6 mV (P = 0.002). Intracellular alkalinization reduced I(K) to 66 +/- 10 pA and depolarized Em to -36 +/- 8 mV (P = 0.009). Single channel studies in perforated outside-out vesicles showed that a decrease in bath pH from 7.35 to 6.00 was accompanied by an increase in the single channel open probability (NPo) from 0.43 to 0.64 at an Em of 15 mV. NPo was also increased in cell-attached patches. The unitary conductance, measured from -100 to +100 mV, was not changed. These results indicate that pH modulates I(K) in rabbit corneal epithelial cells by changes in NPo.

Dye transfer between lens fiber cells and between lens epithelial cells and underlying fiber cells was studied using a wide dynamic range-cooled CCD camera, H2O immersion objectives and image analysis techniques. Each lens was decapsulated by a new technique which leaves the epithelial cells adherent to the lens fiber mass. Lucifer Yellow CH was injected into either single epithelial cells or single fiber cells using the standard whole cell configuration of the patch voltage clamp technique. The results demonstrate extensive dye communication between fiber cells at the lens posterior surface, anterior surface, and equatorial surface. Dye transfer between deep fiber cells was also observed. Dye transfer between ≈10% of epithelial cells and their underlying fiber cells was apparent when care was taken to yield wide dynamic range images. This was required because the relatively high concentration of dye in the epithelial cell masks the presence of much lower dye concentrations in the underlying fiber cell. A mathematical model which includes dye concentration, time, and spatial spread suggests that those epithelial cells that are coupled to an underlying fiber cell are about as well dye coupled as the epithelial cells themselves. The relatively low dye concentration in a fiber cell is due to its larger volume and diffusion of the dye along the axis of the fiber away from the fiber/epithelial junction.

Understanding how behavior is controlled requires that modeling be combined with behavioral, electrophysiological, and neuroanatomical investigations. One problem in studying motor systems is that they have considerable autonomy; they are not driven solely by inputs. Choosing walking as the object of study is promising because it is a comparably simple and easy-to-elicit behavior, but it exhibits the special feature of most motor behavior—the interaction between central, autonomous components and peripheral, sensory influences. This article reviews the control of walking in stick insects, beginning with behavioral studies of single-leg control and the interleg coordinating mechanisms. These behavioral results are tested and supported by modeling the control system in an artificial neural network computer simulation and a six-legged robot. Supporting neurophysiological results also are considered. Together, the results indicate that the high flexibility and adaptability is based on a simple distributed control structure.

We have developed a method to mechanically decapsulate the lens yet leave the epithelial cells attached to the fibers. This method uses divalent ion chelaters to loosen the capsule-epithelial interactions and bumetanide to control cell swelling. Light microscopy, scanning electron microscopy, and in-vitro fluorescence microscopy demonstrate that the capsule is removed and the epithelial cells remain adherent to the fibers when these procedures are used. Ion channel activity and epithelial gap junction communication remain following decapsulation. This decapsulated lens preparation should prove useful for many kinds of lens studies.

A system that controls the leg movement of an animal or a robot walking over irregular ground has to ensure stable support for the body and at the same time propel it forward. To do so, it has to react adaptively to unpredictable features of the environment. As part of our study of the underlying mechanisms, we present here a model for the control of the leg movement of a 6-legged walking system. The model is based on biological data obtained from the stick insect. It represents a combined treatment of realistic kinematics and biologically motivated, adaptive gait generation. The model extends a previous algorithmic model by substituting simple networks of artificial neurons for the algorithms previously used to control leg state and interleg coordination. Each system controlling an individual leg consists of three subnets. A hierarchically superior net contains two sensory and two `premotor' units; it rhythmically suppresses the out-put of one or the other of the two subordinate nets. These are continuously active. They might be called the `swing module' and the `stance module' because they are responsible for controlling the swing (return stroke) and the stance (power stroke) movements, respectively. The swing module consists of three motor units and seven sensory units. It can produce appropriate return stroke movements for a broad range of initial and final positions, can cope with mechanical disturbances of the leg movement, and is able to react to an obstacle which hinders the normal performance of the swing movement. The complete model is able to walk at different speeds over irregular surfaces. The control system rapidly reestablishes a stable gait when the movement of the legs is disturbed.