Predictive values of serum and bulk milk sampling for the presence of persistently infected BVDV carriers in dairy herds

The aim of this study was to examine whether it is possible to predict the presence of persistently infected (PI) animals with bovine viral diarrhoea virus on dairy farms in The Netherlands, based on a few blood samples of the herd, possibly in combination with a bulk milk test for antibodies. In 25 herds with, and 24 herds without, PI animal(s) the probabilities of obtaining at least x antibody positive animals out of a sample of n animals were calculated, with n varying from 3 to 7 and values for x that were considered were n, n - 1 to n - x. This probability, among animals 9-24 months old, ranged from 0.70 to 0.96 for herds with PI animals and from 0.13 to 0.37 for herds without. Using the result of bulk milk testing in addition did not add to the prediction. It was concluded that, due to the high percentage and large variation of antibody positive animals in herds without PI animals, it is not possible to predict the presence of PI animal(s) in dairy herds in The Netherlands using these methods.     

Major outer membrane proteins of Brucella spp.: past,present and future

The major outer membrane proteins (OMPs) of Brucella spp. were initially identified in the early 1980s and characterised as potential immunogenic and protective antigens. They were classified according to their apparent molecular mass as 36–38 kDa OMPs or group 2 porin proteins and 31–34 and 25–27 kDa OMPs which belong to the group 3 proteins. The genes encoding the group 2 porin proteins were identified in the late 1980s and consist of two genes, omp2a and omp2b, which are closely linked in the Brucella genome, and which share a great degree of identity (>85%). In the 1990s, two genes were identified coding for the group 3 proteins and were named omp25 and omp31. The predicted amino acid sequences of omp25 and omp31 share 34% identity. The recent release of the genome sequence of B. melitensis 16 M has revealed the presence of five additional gene products homologous to Omp25 and Omp31. The use of recombinant protein technology and monoclonal antibodies (MAbs) has shown that the major OMPs appear to be of little relevance as antigens in smooth (S) B. abortus or B. melitensis infections i.e. low or no protective activity in the mouse model of infection and low or no immunogenicity during host infection. However, group 3 proteins, in particular Omp31, appear as immunodominant antigen in the course of rough (R) B. ovis infection in rams and as important protective antigen in the B. ovis mouse model of infection. The major OMP genes display diversity and specific markers have been identified for Brucella species, biovars, and strains, including the recent marine mammal Brucella isolates for which new species names have been proposed. Recently, Omp25 has been shown to be involved in virulence of B. melitensis, B. abortus and B. ovis. Mutants lacking Omp25 are indeed attenuated in animal models of infection, and moreover provide levels of protection similar or better than currently used attenuated vaccine strain B. melitensis Rev.1. Therefore, these mutant strains appear interesting vaccine candidates for the future. The other group 3 proteins identified in the genome merit also further investigation related to the development of new vaccines.     

Classification of thermally modified wood by FT-NIR spectroscopy and SIMCA

Quality assessment of thermally modified wood has evolved as one of the major fields in the research on thermal modification of wood. This study investigates NIR spectroscopy in combination with the pattern recognition method of soft independent modeling of class analogies (SIMCA). Focus is put on identifying different treatment intensities of thermally modified samples of beech, ash, and Norway spruce. The results indicate that SIMCA classification based on NIR spectroscopy could be used for quality control of thermally modified wood. The method might be applicable for producers (pre-delivery checks) and customers (reception control). However, transfer from laboratory to industrial conditions needs further investigation.     

Clinical evaluation and prerelease management of American river otters in the second year of a reintroduction study

In the first year (1984) of a reintroduction study, 10 American river otters (Lutra canadensis) from Louisiana were transported to Oklahoma, held for 5 days for clinical evaluation, surgical implantation with intra-abdominal radiotelemetry devices, and then released in Oklahoma. Four of 10 otters released died within 32 days. Clinical evaluation indicated that respiratory tract disease, bacterial and parasitic infections, and inanition may have contributed to the death of these otters. In the second year (1985) of the study, an exotic feline diet was fed, and the holding period for 10 otters was increased to provide time for evaluation and treatment before surgery, postsurgical acclimation to Oklahoma, and reevaluation before release. Although the initial clinical findings on otters in the second year were similar to those found in the first year, otter body weights increased, and the prevalence and severity of clinical abnormalities decreased with treatment during the second-year holding period. Three of 10 second-year otters died during the holding period, and contributing causes of death were determined to be: trauma (hepatic hematoma), inanition, renal disease, pneumonia, salmonellosis (Salmonella anatum), and a retropharyngeal abscess (Klebsiella pneumoniae). Seven healthy otters were reintroduced into Oklahoma in 1985, and postrelease deaths were not experienced.     

Evaluation of five different methods for routine diagnosis of rabies

Brain tissue from 187 animals of different species was investigated by means of fluorescent antibody test, peroxidase anti-peroxidase technique, mouse inoculation test and cell culture technique for a diagnosis of rabies. With peroxidase anti-peroxidase technique the rabies specific reaction comprised inclusion bodies and a granular staining of the cytoplasm of affected cells. A specific positive reaction was found only in neurons, in which perikaryon as well as cell processes were affected. Fluorescent antibody test and peroxidase anti-peroxidase technique detected 98% each, mouse inoculation test 95% and cell culture technique 81% of the rabies positive animals. In conclusion, peroxidase anti-peroxidase technique allows a highly reliable diagnosis of rabies when only formalin-fixed and paraffin-embedded material is available. Histopathological alterations comprising Negri bodies, inflammatory and degenerative lesions were encountered in 53% of the rabies positive brains.     

Population ecology and prey consumption by fathead minnows in prairie wetlands: importance of detritus and larval fish

Abstract –  The fathead minnow Pimephales promelas occurs in high densities in wetlands of the prairie pothole region (PPR) of North America, but food resources sustaining these populations are poorly known. We assessed population dynamics and prey consumption of fathead minnow populations in three PPR wetlands for 2 years. Fish density peaked at 107 fish per m² for all age classes combined. Larval and juvenile fish dominated these populations in terms of abundance and accounted for 83% of total prey consumption. Detritus dominated fish diets, representing 53%, 40% and 79% of diet mass for larval, juvenile and adult fish respectively. Detritus consumption was positively related to minnow density and negatively related to invertebrate abundance, but only for adult fish. Seasonal production:biomass ratios were unrelated to proportions of detritus in the diet for all ages of fish, indicating that detritus is an important food resource capable of meeting metabolic demands and sustaining fish growth in high-density populations. Detritus consumption may also weaken links between abundance of invertebrate prey and minnows, promoting dense fish populations with strong, consistent influences on wetland ecosystems.     

Evaluation of the germ plasm collection of safflower,Carthamus tinctorius L. VII. Variability of capitulum width and outer involucral bracts' dimensions

Summary A germ plasm collection of safflower, Carthamus tinctorius L., with about 900 lines from over twenty countries was evaluated in Utah, USA for head width and outer involucral bracts (OIB) dimensions, traits affected by both human and natural selection. The regional germ plasm pools contained considerable variability for these traits. Plants bearing short or long as well as narrow or wide OIB were well adapted. Geographical clines were detected for the means of OIB dimensions, indicating possible gene flow. The correlations of the OIB dimensions with yield, yield components, oil content and growing period were not instructive and at times very inconsistent. Primary head diameter varied considerably within the regional gene pools. Its correlations with yield/plant, number of heads/plant, seed weight and oil content were inconsistent. Capitulum width was positively and significantly correlated with the number of seeds per head. Head diameter, however, can vary considerably without affecting seed yield per unit area.     

Erhebungsuntersuchung zur Nährstoffversorgung von Picea omorika im Zusammenhang mit dem Omorikensterben

A survey investigation of the relationship between nutritional factors and the decline of Picea omorika growth Soil and needle samples were collected from 193 sites of Picea omorika (mostly in private gardens) in Northern Germany ranging from normal to seriously damaged plants. The needles were analysed for N, P, K, Ca, Mg, Cu, Zn, Mn, Fe, B, Cl and Na. In the soil samples pH, P, K and Mg were determined.

• 1 In 54 cases (= 30,3% of the 178 sites with injured trees) the cause of the damage could not be established. In a few cases only (12 sites = 6,7%) Mg deficiency seemed to have caused the injuries. But in a large number of cases the needles showed high Cl contents, hence Cl toxicity was the most important cause (103 sites = 57,9%) of the damage.
• 2 The critical content of needles sampled in autumn is 0,27 % C1. Above this value CI-toxicity is highly probable and between 0,22 and 0,27 % CI it is possible.
• 3 High Cl-content is associated with mottled chlorosis and in many cases also with a brown discoloration beginning at the tip of the needle. The symptoms are usually stronger at the tips of branches than in central or basal parts.
• 4 Susceptibility to Cl-toxicity is similar for Picea omorika and Picea abies.
• 5 C1-toxicity may be caused by high application of deicing salt and Cl-containing fertilizers. Some of the fertilizers specially developed for the nutrition of conifers even contain too much Cl.