Control and eradication strategies for classic fowl plague in Germany and the European Union

The huge potential economic impact of highly pathogenic avian influenza (HPAI) substantiates specific and rigorous legal regulations worldwide. According to the O.I.E. Terrestrial Animal Health Code fowl plague is a notifiable disease. International trading activities concerning poultry and poultry products originating from countries with active HPAI are rigorously restricted. In EU member states directive 92/40/EEC subsumes measures against fowl plague and has been transferred into German legislation by the "Geflügelpest-Verordnung". These acts specify that vaccination against HPAI is principally prohibited. The aim of all sanctions is the extinction of disease and the eradication of the causative agent. However, HPAI viruses, exclusively belonging to subtypes H5 and H7, can re-emerge de novo from progenitor viruses of low pathogenicity which are perpetuated in the wild bird population. An outbreak of HPAI requires prompt action by a stamping out strategy. Fast and accurate diagnosis, a strict stand-still and the culling of affected flocks are at the basis of success. In areas with a high density of poultry holdings preemptive culling and creation of buffer zones, devoid of susceptible poultry, may be neccessary. In these cases emergency vaccinations can be considered as a supportive measure in order to limit mass culling. Vaccinations on merely prophylactic grounds, not being connected to acute outbreaks, should be avoided beware of selective pressures on the virus leading to antigenic drift and escape of vaccine-induced immunity. Instead, high standard biosecurity measures, particularly limiting direct and indirect contacts with wild birds, should be maintained.     

Neurotropism of highly pathogenic avian influenza virus A/chicken/Indonesia/2003 (H5N1) in experimentally infected pigeons (Columbia livia f. domestica)

This investigation assessed the susceptibility of experimentally infected pigeons to the highly pathogenic avian influenza virus (HPAIV) H5N1 that caused recent outbreaks of avian influenza in birds and humans in several countries of Asia. For this purpose 14 pigeons were infected ocularly and nasally with 10(8) EID50 and clinical signs were recorded and compared with five chickens infected simultaneously as positive controls. The chickens demonstrated anorexia, depression, and 100% mortality within 2 days postinoculation. Three of the pigeons died after a history of depression and severe neurological signs consisting of paresis to paralysis, mild enteric hemorrhage, resulting in a mortality of 21%. Gross lesions in these pigeons were mild and inconsistent. Occasionally subcutaneous hyperemia and hemorrhage and cerebral malacia were observed. Microscopic lesions and detection of viral antigen were confined to the central nervous system of these pigeons. In the cerebrum and to a minor extent in the brain stem a lymphohistiocytic meningoencephalitis with disseminated neuronal and glial cell necrosis, perivascular cuffing, glial nodules, and in one bird focally extensive liquefactive necrosis could be observed. The remaining nine pigeons showed neither clinical signs nor gross or histological lesions associated with avian influenza, although seroconversion against H5 indicated that they had been infected. These results confirm that pigeons are susceptible to HPAIV A/chicken/Indonesia/2003 (H5N1) and that the disease is associated with the neurotropism of this virus. Although sentinel chickens and most pigeons did not develop disease, further experiments have to elucidate whether or not Columbiformes are involved in transmission and spread of highly pathogenic avian influenza.     

Variations in the severity of phocid herpesvirus type 1 infections with age in grey seals and harbour seals

The data recorded during an outbreak of phocid herpesvirus type 1 infection among 19 harbour seals and 29 grey seals being nursed in a seal rehabilitation centre in The Netherlands in 1998 were used, together with data from similar outbreaks in previous years, to compare the clinical signs observed in the two species at different ages. The severity of the disease was inversely correlated with age in the harbour seals, and the infected harbour seals generally developed more severe clinical signs than the infected grey seals.     

New insights into genotypic thermodependency of cytoplasmic male sterility for hybrid barley breeding

The cytoplasmic male sterility (CMS) system msm1 in barley is known to be thermosensitive, sometimes resulting in spontaneous fertility restoration in the absence of the corresponding restorer gene Rfm1. Here, we investigated genotypic differences concerning temperature sensitivity and the plant developmental stage at which elevated temperature induces spontaneous fertility restoration in three CMS mother lines. While one line stayed completely male sterile, a significantly higher fertility was observed in two lines after treatment from growth stage DC 41 until maturation. Microscopic analysis revealed that sterile anthers contained neither intact pollen, nor remains of aborted pollen grains, whereas pollen was visible in anthers of potentially fertile plants. We conclude that the barley CMS system affects anther and pollen development prior to meiosis. Elevated temperature during heading and flowering can lead to a spontaneous fertility restoration by reactivating pollen growth. Nevertheless, genotypic variation exists enabling the selection for stable CMS mother lines and the development of F₁ hybrids with high hybridity. As spontaneous fertility restoration due to environmental effects is difficult to phenotype, further investigations will focus on the development of molecular markers for marker‐assisted selection.     

The oat line Pc54 as a source of resistance to crown rust,stem rust and powdery mildew in Europe

Summary The oat line Pc54 was found to be resistant to powdery mildew under both field and glasshouse conditions. The ratio of resistant to susceptible F₂ and F₂ progeny of a cross between a selection from the Pc54 line (Cc7422) and a susceptible cultivar (Selma) showed that, in addition to carrying the crown rust resistance gene Pc54 and the pg15 gene for stem rust resistance, the mildew resistance of the Pc54 line was conditioned by a single incompletely dominant gene along with additional factors which modified the expression of resistance. Previous results, that there was no linkage between genes Pc54 and Pg15, were confirmed. In addition, there was no evidence of linkage between the mildew resistance gene and gene Pc54. Evaluation of selections from within the Pc54 line showed that the expression of both stem rust and mildew resistance was modified by, or linked to, plant height. The effectiveness of genes Pc54 and Pg15, as measured by virulence frequencies, in central and eastern Europe is described.     

Earthquake source fault beneath Tokyo

Devastating earthquakes occur on a megathrust fault that underlies the Tokyo metropolitan region. We identify this fault with use of deep seismic reflection profiling to be the upper surface of the Philippine Sea plate. The depth to the top of this plate, 4 to 26 kilometers, is much shallower than previous estimates based on the distribution of seismicity. This shallower plate geometry changes the location of maximum finite slip of the 1923 Kanto earthquake and will affect estimations of strong ground motion for seismic hazards analysis within the Tokyo region.     

No Virological Evidence for an Influenza A ‐ like Virus in European Bats

New members of the influenza A virus genus have been detected recently in bats from South America. By molecular investigations, using a generic real‐time RT‐PCR (RT‐qPCR) that detects all previously known influenza A virus subtypes (H1‐H16) and a newly developed RT‐qPCR specific for the South American bat influenza‐like virus of subtype H17, a total of 1571 samples obtained from 1369 individual bats of 26 species from Central Europe were examined. No evidence for the occurrence of such influenza viruses was found. Further attempts towards a more comprehensive evaluation of the role of bats in the ecology and epidemiology of influenza viruses should be based on more intense monitoring efforts. However, given the protected status of bats, not only in Europe, such activities need to be embedded into existing pathogen‐monitoring programs.     

REVIEW: Wild Rice: Both an Ancient Grain and a Whole Grain

Wild rice (Zizania spp.) grows in shallow waters of North America and is distinct from brown and white rice (Oryza spp.). The recent trends toward gluten‐free foods and ancient grains present an opportunity for increased interest in the health benefits of wild rice. Wild rice is classified as a whole grain and typically contains 75% carbohydrate, 6.2% dietary fiber, 14.7% protein, and 1.1% lipids. Wild rice is a good source of dietary fiber and has nearly double the amount of protein of white rice. The lipid content is low; however, most of the lipids are essential omega‐6 (35.0–37.8%) and omega‐3 (20.0–31.5%) fatty acids. In addition to macronutrient content, wild rice contains phytosterol levels several times higher than white rice. Furthermore, the antioxidant activity of wild rice is 10–15 times higher than white rice. A series of rat studies in which wild rice was added to a high fat, high cholesterol diet found significant attenuation of serum free fatty acids, total cholesterol, and triglyceride levels while maintaining higher high‐density lipoprotein levels compared with a control diet. The exact explanation of the protective mechanism of wild rice is uncertain, but the dietary fiber, phytosterol, or antioxidant capacity of wild rice may be the reason for it. Current interest in whole grains and gluten‐free diets, as well as antioxidants and phytochemicals, makes wild rice an attractive grain addition to the diet.     

Potato composition: I. Tissue selection and its effects on solids content and amylose/amylopectin ratios

Solids content and amylose/amylopectin ratios were determined in different parts of tubers of White Rose, Red La Soda, Kennebec, Russet Burbank, Norchip and Lenape at harvest, after storage at 7 C for 2 and 4 mo, and after reconditioning at 20 C for 3 wk following each storage period. In all cultivars, solids content was greatest in stem-end, lower in bud-end and lowest in core tissue. The relationships for distribution of solids among the different parts of the tubers was not changed by storage treatments in any of the cultivars. Amylose/amylopectin ratios were similar in all parts of the tuber. Both the solids content and amylose/amylopectin ratio were changed by storage, but not uniformly in all cultivars.