Spatial Predictive Context Speeds Up Visual Search by Biasing Local Attentional Competition.

The human visual system is equipped to rapidly and implicitly learn and exploit the statistical regularities in our environment. Within visual search, contextual cueing demonstrates how implicit knowledge of scenes can improve search performance. This is commonly interpreted as spatial context in the scenes becoming predictive of the target location, which leads to a more efficient guidance of attention during search.

No exploitation of temporal sequence context during visual search.

The human visual system can rapidly extract regularities from our visual environment, generating predictive context. It has been shown that spatial predictive context can be used during visual search. We set out to see whether observers can additionally exploit temporal predictive context based on sequence order, using an extended version of a contextual cueing paradigm.

A study on the severity and relevance of porcine circovirus type 2 infections in Dutch fattening pigs with respiratory diseases.

This study was set up to get more insights in the severity and relevance of porcine circovirus type 2 (PCV2) infections in Dutch fattening farms in an endemic PCV2-situation with no clinical signs of post-weaning multisystemic wasting syndrome (PMWS). In part A of the study, in total 29 commercial fattening farms with varying percentages of pneumonia and pleurisy at slaughter were examined. Blood samples were collected at random by cross-sectional sampling; 10 in the age of 10-12 weeks, 10 at the age of 16 weeks and 10 blood samples at the end of the finishing period (20-22 weeks of age).

[Effect of the Stellamune Mycoplasma vaccine on growth, energy conversion, death, and medication use in fattening pigs on a pig farm chronically infected with Mycoplasma hyopneumoniae].

The effect of Stellamune Mycoplasma vaccine, administered to piglets aged 2-15 days and then 13-15 days later, on daily weight gain, energy conversion, and use of medication was examined in fattening pigs on a chronically Mycoplasma hyopneumoniae infected pig farm. Half of the piglets were vaccinated and the other half acted as controls. In the study design, half of the pens in the fattening unit were allocated to vaccinated pigs; the other half to non-vaccinated pigs, pen was the experimental unit.

[Analysis of survey data about the effect of vaccination of sows against blue pig abortion (PRRS) in the Netherlands].

Questionnaires were used to collect information on the experience of pig breeders with the vaccination of sows against PRRS. There was a 1-year interval between the two questionnaires. Sixty-two pig breeders returned the first questionnaire and 36 returned the second questionnaire.

Use of colostrum to detect antibodies against glycoprotein I of Aujeszky's disease virus.

Serum and colostrum samples taken from 499 sows from five herds of pigs endemically infected and vaccinated against Aujeszky's disease virus, were used to investigate whether colostrum could be used to detect antibodies against glycoprotein I (gI) of the virus. Using serum as the reference, the test applied to colostrum had a sensitivity of 97 per cent and a specificity of 88 per cent. When samples were taken from 50 sows from a gI seronegative vaccinated herd, one colostrum sample was gI-positive, giving a specificity for the test of 98 per cent.

[The effect of parvovirus vaccination in sows through their 4th parity and the role of influenza H1N1 virus].

The effects of vaccination of a porcine parvovirus (PPV) in gilts and the first four litters were studied in a pig-breeding herd. In addition to determination of the technical results, PPV and influenza (H1N1) titres were measured. From the serological findings it was apparent that PPV and influenza (H1N1) virus circulated during the trial.

[Determination of estrone sulfate levels in the blood and urine of pigs].

The concentration of oestrone sulphate was determined in plasma as well as in urine to verify early pregnancy in pigs (within 24-29 days after mating). The threshold level in plasma was 0.70 ngr/ml.

[Effects of the addition of increased nitrates to the drinking water of fattening pigs and weaned piglets].

Three experimental studies were done on the effects of increased concentrations of nitrate in the drinking water of weaned piglets and flattening pigs throughout the weaning and fattening periods respectively on the experimental piggery in Raalte for pigs in the northern and eastern Netherlands. To begin with, prospective studies were done in three times four individually housed experimental animals which were given 100, 200 and 500 mg of nitrate per litre of drinking water respectively throughout the fattening period. The results obtained were compared with the findings in twenty controls.

A field evaluation of Nobi-Vac atrophic rhinitis vaccine.

A field trial was carried out with Nobi-Vac AR vaccine in 11 swine breeding herds. One herd suffered from severe B. bronchiseptica (BB+) rhinitis in piglets, while no clinical Atrophic Rhinitis (AR) was observed.

[Study of porcine parvovirus antibodies on a breeding farm].

Serological examination of porcine parvovirus (PPV) haemagglutinating antibodies is reported in replacement gilts after a PPV infection on a large farm. It seems that PPV is no longer active on the farm after PPV infection.