Viral and Bacterial Pathogens in Bovine Respiratory Disease in Finland

Pathogens causing bovine respiratory tract disease in Finland were investigated. Eighteen cattle herds with bovine respiratory disease were included. Five diseased calves from each farm were chosen for closer examination and tracheobronchial lavage. Blood samples were taken from the calves at the time of the investigation and from 86 calves 3–4 weeks later. In addition, 6–10 blood samples from animals of different ages were collected from each herd, resulting in 169 samples. Serum samples were tested for antibodies to bovine parainfluenza virus-3 (PIV-3), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCV), bovine adenovirus-3 (BAV-3) and bovine adenovirus-7 (BAV-7). About one third of the samples were also tested for antibodies to bovine virus diarrhoea virus (BVDV) with negative results. Bacteria were cultured from lavage fluid and in vitro susceptibility to selected antimicrobials was tested. According to serological findings, PIV-3, BAV-7, BAV-3, BCV and BRSV are common pathogens in Finnish cattle with respiratory problems. A titre rise especially for BAV-7 and BAV-3, the dual growth of Mycoplasma dispar and Pasteurella multocida, were typical findings in diseased calves. Pasteurella sp. strains showed no resistance to tested antimicrobials. Mycoplasma bovis and Mannheimia haemolytica were not found.     

Nanoplanktonic coccolithophorids (Prymnesiophyceae, Haptophyceae) from the Weddell Sea, Antarctica

The examination of whole mounts prepared for transmission electron microscopy has resulted in the finding of thirteen taxa of nanoplanktonic coccolithophorids from the Weddell Sea, Antarctica. The material was collected as part of the AMERIEZ programme, March 1986. Cold-water adapted nanoplanktonic coccolithophorids have previously been shown to constitute a recurrent plankton element at subarctic and arctic localities. Three of the Weddell Sea species, Wigwamma annulifera, W. arctica , and Papposphaera sagittifera , are conspecific with northern hemisphere material, while two species, Calciarcus alaskensis and Turrisphaera arctica , are possibly identical with previously described arctidsubarctic material. Six taxa new to science have been described from the Weddell Sea, Wigwamma antarctica, W. triradiata, Trigonaspis melvillea, Pappomonas weddellensis, Papposphaera obpyramidalis , and P. simplicissima . The cooccurrence of identical forms at the two poles, and the fact that the species described are allocated to "arctic" genera, indicate a geologically relatively recent exchange of biological material between the poles.     

Zur Paarbildung der Uferschwalbe (Riparia riparia)

Zusammenfassung Uferschwalben kehren aus den afrikanischen Winterquartieren in Trupps beiderlei Geschlechts zurück. Erste Beringungsergebnisse belegen, daß zunächst mehrjährige, vermutlich untereinander bekannte Vögel eintreffen, die den Brutplatz aus vergangenen Brutperioden her kennen. Die Masse der später ankommenden Vögel dürfte weitgehend aus einjährigen oder ortsfremden Uferschwalben bestehen, die sich größtenteils erst während der Paarbildung persönlich kennenlernen. Der anfängliche Schwarmzusammenhalt der nacheinander eintreffenden Trupps führt zur Bildung von Subkolonien, die für Brutplätze ab einer bestimmten Größenordnung typisch sind. Uferschwalben- gründen nacheinander mehrere Reviere, d. h. sie besetzen Steilwandbereiche, in denen sie ausschließlich mit den Füßen eine Röhre oder Mulde graben, singen und Bogenflüge starten. Bis auf singende oder bekannte werden Artgenossen im Revier geduldet. Uferschwalben- suchen besetzte Reviere auf. Ohne Röhrenbindung verhalten sie sich still und unauffällig, ihre Grabungsaktivitäten sind von untergeordneter Bedeutung. Die Bindung an ein bestimmtes Revier entwickelt sich individuell verschieden und entscheidet über den Abschluß des Röhrenbaues (Herstellung der Nistkammer). Reviere ohne dauerhafte -Bindung werden von den aufgegeben. Aktivitäten, die auf wachsende Revierbindung eines hindeuten, sind: häufige oder/und länger dauernde Aufenthalte des in einem besetzten Revier und sporadisches Mitgraben; aggressives Verhalten gegenüber Artgenossen (i. d. R. fremde ), die im Revier landen wollen; gemeinschaftlicher, leiser Gesang von und im Röhrenbereich. Aktivitäten, die für eine vollzogene Paarbildung sprechen, sind: Fertigstellen der Röhre durch Grabung der Nestkammer; längere gemeinsame Aufenthalte innerhalb und außerhalb der Röhre; Voranfliegen des beim Röhrenanflug; Übernachten von und in der Röhre; Nestbau; ausdauernde Verfolgungsflüge während der Kopulationsphase. Die Paarbildung ist demnach ein individueller Prozeß, bei dem die Aktivitäten der im Revier als Werbung, die der als Revierwahl interpretiert werden.

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On pair-formation in the Sand Martin,Riparia riparia

Summary European Sand Martins arrive at their breeding sites in flocks of usually unmated and . Ringing results of a large population in NW-Germany and own observations indicate that the first flocks about a dozen individuals with an approximately balanced sex ratio appear at traditional breeding places and consist of older, experienced resident birds (presumably acquainted with one another). The birds arriving over the next several weeks are mainly first-year or non-resident individuals. The flocks arrive separately in areas with suitable sandcliffs, synchronize the pair-formation activities and avoid disturbances among paired and unpaired birds. This behaviour causes the formation of subcolonies, which are typical for all densely occupied breeding places. Each settles on a fixed area on the sandcliff (territory) in order to excavate a burrow, to sing the territory-song (fig. 2 b) and to perfor the territory-circle-flight (fig. 2 c, 4 a). Silent birds (normally ) are welcomed or tolerated by the resident . The sexes are monomorphic and therefore courtship displays of the are non-aggressive until establishment of pair-bonds. Only intruding singing or individually known neighbouring are driven away, usually at early stages of territory occupation. Unmated are normally shy and very sensitive to protracted disturbances. visit several occupied territories of the colony (fig. 1–3) in order to choose a burrow. leave territories which do not attract a . They settle new territories on the sandcliff, causing a surplus of burrows compared to breeding pairs in the colony. Activities which indicate the development of pair-bonds are: regular visits of a to a particular occupied territory with sporadic excavations by the ; aggressive activities of the towards other visitors usually , but sometimes at first even against the resident (i. e.: vocal threats, bill-gaping, pecking or pushing with the bill or vigorous face-to-face fights, fig. 3 b, 3 c). and sing the soft mating song at or in the burrow (fig. 1 c). Activities which indicate completed pair-bonds are: completion of the burrow by digging the nestchamber, predominantly done by the ; both birds staying together over long periods, both inside and outside the burrow; invitation-flight by the (fig. 4 b); and spending the night together in the burrow; beginning of nest-building, first only by the , then by both birds and finally only by the , accompanied by the (guarding-flight;, fig. 4c); mate-pursuit flights (sexual chases) during copulation phase, in which the singing pursues the silent , often accompanied by other (cp. fig. 4 d). Pair-formation in the Sand Martin occurs on individual territories and not, according toHickling (1959), within the flock.

     

Haemolysis of rabbit erythrocytes by a lectin from the seeds of<Emphasis Type="Italic">Croton tiglium</Emphasis>

The kinetics of haemolysis of rabbit erythrocytes byCroton tiglium lectin was studied as a function of concentration of the lectin and erythrocytes. The length of the prelytic period decreased with increasing lectin concentrations, indicating that the secondary events at the membrane which follow the binding of the lectin to cell surface carbohydrate receptors are accelerated at higher surface concentrations of the lectin. The rate or extent of haemolysis was not affected by the inclusion of ions like K⁺, Ca²⁺ and Mg²⁺ in the medium or by the substitution of ionic medium by a non-ionic medium. The inhibition of haemagglutination and haemolysis of rabbit red cells byCroton tiglium lectin by antilectin rabbit serum was observed. A possible mechanism of haemolysis by the lectin is discussed.