RADIOGRAPHIC CHANGES IN TESTES OF BULLS INFECTED WITH BESNOITIOSIS

Ten beef bulls infected with Besnoitiosis were examined radiographically and pathologically. Eight of these were slaughtered soon after diagnosis; two were left for a six-month observation period. The radiographic findings were focal and branching-tree calcification of the testes. Histopathologic examination proved these calcifications to be necrotic sections of the seminiferous tubules. Radiography of the testes as a means of evaluating the fertility status of the infected bull is recommended.     

Effect of induced compaction by wheel traffic on soil physical properties and yield of maize in Romania

Results of field experiments with soil compaction induced by wheel traffic applied uniformly to cover the entire surface of the experimental plots are reported. Compaction was done immediately before sowing, and each year, in each location, the same treatments were repeated on the same plots. The number of tractor passes varied between 0 and 30. The experiments were conducted during the 1978–1981 period in four locations with different soil and climatic conditions.Changes in soil physical properties, as well as in the yield of maize grain, were shown to be related to the number of tractor passes according to regression formulae of the type: Y = aX^b. Most of the changes were recorded between 0 and 8–10 passes, while with more than 15–20 passes changes became negligible. The average maximum increase in bulk density was 20–25% as compared with the non-compacted control plot, and the average maximum decrease in yield was 46%. Moisture content in the compacted control plot, and the was 2–3% (w/w) lower than in the control plot, except for the soils with poor drainage where the lower part of the compacted topsoil showed an increase in moisture content. Air content in the compacted plots often dropped below 10, and occasionally to nearly 0% (v/v). For three of the four locations, grain yield of maize linearly decreased by 13 kg ha^?1 (or 0.18% of the control plot yield) for each 1 kg m^?3 increase in bulk density.     

Satellite remote sensing of breeding habitat for an African weaver-bird

Data derived from the Advanced Very High Resolution Radiometer (AVHRR) on board the NOAA series of operational, polar orbiting, meteorological satellites have previously been shown to be quite useful for monitoring vegetation dynamics at scales ranging from regional (10⁴ km²) to global. In this report, we demonstrate that these same data can be used to monitor potential breeding habitat for a highly mobile, granivorous African weaver-bird, the red-billed quelea (Quelea quelea). This species is often considered to be an agricultural pest, affecting cereal production throughout sub-Saharan Africa. The temporal resolution and very large (continental) spatial coverage provided by these data can provide a unique context within which to examine species distribution and abundance patterns.     

Characterization of pathogenic Escherichia coli isolated from humans in Austria: phenotypes, toxin gene types and epidemiology

One hundred and ten clinical Escherichia coli isolates of serovar O157 (n = 102) and O26 (n = 8) were characterized for the presence of putative virulence genes by PCR. All but one of these isolates contained the eae gene. The EHEC-hly gene could be detected in all E. coli O157 and in 50% of E. coli O26 isolates. Forty-five (40.9%) of the 110 E. coli were positive for both stx(1) and stx(2) genes, 2 (1.8%) isolates were positive for stx(1) and 57 isolates (51.8%) were positive for stx(2) only. Among the 102 stx(2) positive isolates, 14 (13.7%) E. coli O157 contained also the stx(2c) variant gene. No other stx(2) variant was identified. Six clinical isolates (five E. coli O157:H7 and one E. coli O26) did not contain stx genes. Ten non-pathogenic E. coli isolates which were amplified as controls didn't contain any stx and eae gene but two of the ten strains contained the EHEC-hly gene. By their growth on chromogenic media, all but two of 50 E. coli O157 could be differentiated from eight E. coli O26 and 10 non-pathogenic E. coli. Sixty-one of the O157:H7 isolates were further subjected to pulsed-field gel electrophoresis (PFGE) which identified 49 distinguishable patterns. In five cases where contact infection among family members was suspected, indistinguishable PFGE patterns confirmed the epidemiological relatedness of the isolates. Moreover, two PFGE clusters were identified which comprised five and three strains, respectively. These findings indicate the occurrence of both family and diffuse outbreaks of E. coli O157 infections in Austria during recent years and demonstrate the need for molecular subtyping of these pathogens.     

Atomabsorptionsflammenphotometrische Manganbestimmung in Pflanzenaschen

In 3 Lysimetern (Standort Brandis bei Leipzig) mit Bodenmonolithen (Lys. 5 ‐ Braunerde, Lys. 7 ‐Pseudogley, Lys. 10 ‐ Schwarzerde) wurden im September 1994 vergleichend zu Bodenprofilen der Herkunftsflächen schichtweise bis Im Tiefe Untersuchungen zum Vorkommen von Lumbriciden durchgeführt. Die Anzahl der Regenwürmer stieg mit zunehmendem pH‐Wert und C_org‐Gehalt in der Reihenfolge Lys. 10 > Lys. 7 > Lys. 5. Auf Grund des geringen Probenumfangs können keine flächenbezogenen Aussagen abgeleitet werden. Es wurden überwiegend endogäische Würmer gefunden. Es ließ sich nicht mit Sicherheit feststellen, ob die anözischen Würmer in den Lysimetern leben oder sich nur kurzzeitig dort aufhalten. Durchgängige vertikale Regenwurmgänge, wie sie abschnittsweise in verschiedenen Tiefen an senkrechten Schnitten mit Hilfe der Computertomographie nachgewiesen wurden, würden für einen ständigen Aufenthalt anözischer Arten sprechen. Nur dann sind Schlußfolgerungen zur Tätigkeit der Tiefgräber und deren Einfluß auf Infiltration, Nähr‐ und Schadstofftransport möglich. Vergleichsuntersuchungen an Bodenprofilen der Herkunftsflächen zeigten, daß wohl auf Grund der andersartigen Bewirtschaftung nur eine partielle Übereinstimmung im Regenwurmvorkommen zwischen Lysimetern und Bodenprofilen besteht. Da auch viele Ackerböden einen sehr geringen Regenwurmbesatz aufweisen, scheint eine Übertragung der Lysimeterergebnisse auf das Freiland unter diesem Gesichtspunkt möglich zu sein.     

保护性农业带来的光明

每一个热心农业工作的人迟早都会对目前耕作的方法提出疑问。耕地的保护已经研究和试验很长时间了，然而，耕地的持续退化和侵蚀却无处不在。约定俗成的传统耕作方式，是耗尽土壤中的有机物质，并造成土壤退化的主要原因。相反，保护性农业，由于省去了种植前的土壤准备工作，给农业带来了光明。     

Seroprevalence for norovirus genogroups GII and GIV in captive non‐human primates

Noroviruses (NoVs) are a major cause of epidemic gastroenteritis in children and adults. Several pieces of evidence suggest that viruses genetically and antigenically closely related to human NoVs might infect animals, raising public health concerns about potential cross‐species transmission. The natural susceptibility of non‐human primates (NPHs) to human NoV infections has already been reported, but a limited amount of data is currently available. In order to start filling this gap, we screened a total of 86 serum samples of seven different species of NPHs housed at the Zoological Garden (Bioparco) of Rome (Italy), collected between 2001 and 2017, using an enzyme‐linked immunosorbent assay (ELISA) based on virus‐like particles (VLPs) of human GII.4 and GIV.1 NoVs. Antibodies specific for both genotypes were detected with an overall prevalence of 32.6%. In detail, IgG antibodies against GII.4 NoVs were found in 18 Japanese macaques (29.0%, 18/62), a mandrill (10.0%, 1/10), a white‐crowned mangabey (16.6%, 1/6) and in an orangutan (33.3%, 1/3). Twelve macaques (19.3%, 12/62), five mandrills (50.0%, 5/10), two chimpanzees (100%, 2/2) and a white‐crowned mangabey (16.6%, 1/6) showed antibodies for GIV.1 NoVs. The findings of this study confirm the natural susceptibility of captive NHPs to GII NoV infections. In addition, IgG antibodies against GIV.1 were detected, suggesting that NHPs are exposed to GIV NoVs or to antigenically related NoV strains.