[Determination of breakpoints for veterinary medically relevant antibiotics for resistance assessment of veterinary pathogens]. / Zur Festlegung von Grenzwertkonzentrationen (breakpoints) für veterinärmedizinisch relevante Antibiotika zur Resistenzbeurteilung bei tierpathogenen Erregern.

This article describes the meaning of the term clinical breakpoint. This is followed by a discussion of the parameters that need to be considered when setting valid breakpoints for active substances in veterinary medicine; in doing so we closely follow equivalent regulations and guidelines on the establishment of breakpoints in human medicine. Along with pharmacokinetic data and the results of clinical efficacy tests, susceptibility data of relevant organisms play a key role in the establishment of breakpoints. Published breakpoints are currently only available for a few modern drugs in veterinary medicine.

[Guidelines for planning studies to determine the resistance of infectious agents of veterinary relevance]. / Leitfaden zur Planung von Studien zur Erfassung der Resistenzsituation bei veterinärmedizinisch relevanten Infektionserregern.

This paper describes the most important criteria for the planning of statistically sound and representative studies on the prevalence of antimicrobial resistance among pathogenic bacteria from animals. The statistical design of the study is of particular importance and therefore described in some detail. The existing published data about antimicrobial resistance are mostly retrospective summaries of results and do not give a true picture of the resistance situation. The authors propose to conduct a pilot study initially because many basic elements for a sound study design are still not known. The systematic recording and assessment of the target variables including the necessary quality assurance are an important prerequisite. Moreover, potential cause variables can be further narrowed down and conclusively identified. To ensure the representativity of the cross-sectional study and avoid potential bias, it is important to achieve the highest possible response rate. This will form the basis of a scientifically sound resistance monitoring programme which should be the joint responsibility of regulatory authorities, industry and academia.

[Observations on resistance monitoring in animal health]. / Anmerkungen zum Resistenzmonitoring in der Tiergesundheit.

This article describes conventional procedures which are used for susceptibility testing of bacteria isolated from food producing animals against anti-infective substances. Interpretation of results obtained from the different test methods and the conditions necessary to conduct these tests in view of a meaningful resistance monitoring are discussed. Currently, published data about the resistance situation in veterinary medicine are either not representative or have been determined under suboptimal conditions. In view of the public and often non-scientifically based discussion about bacterial resistance it is absolutely necessary to generate a scientifically valid database.

The growth of memory during infancy.

Eight middle class infants were administered a series of tasks over a nine month period from 5 to 14 months of age. Major procedures included object permanence, vacillation, memory for locations and pictures, and reaction to unfamiliar adults and to separation. The results suggested that during the last half of the first year there is a major enhancement in the ability to retrieve a representation of a past event, to compare that representation with present experience, and to tolerate both longer delays between an original and transformed event and greater interference during those delays. It was suggested that many of the diverse phenomena that appear during the last half of the first year are mediated, in part, by an amplification of memorial capacity.

Color vision and hue categorization in young human infants.

Two studies examined the organization of color perception in 4-month-old human infants. In Study 1, infants looked at selected spectral stimuli repeatedly until their visual attention waned. The stimuli represented instances of basic adult hue categories - blue, green, yellow, and red. Following habituation, infants were shown a series of wavelengths which were the same as or different from the stimuli first seen. Analyses of infant attention during this dishabituation phase of the study indicated that infants categorize wavelengths by perceptual similarity; that is, they see hues in the spectrum much as adults do. In Study 2, a group of infants who looked at the alteration of two wavelengths from the same hue category habituated as did the group of infants who looked at the repitition of a single wavelength from that category, but a group of infants who looked at two wavelengths from different categories habituated at a slower rate. Data from the two studies suggest a high degree of organization of the color world prior to language acquisition.

The categories of hue in infancy.

Infant looking time was monitored during habituation to the repeated presentation of a wavelength stimulus selected from one basic adult hue category and after a change in stimulation. Recovery from habituation was greater to a wavelength selected from an adjacent hue category than to a wavelength from the same category even though these two stimuli were equally distant (in nanometers) from the habituation wavelength. Differential responding evidenced infants' categorical perception of hue; that is, infants see the physically continuous spectrum as divided into the hue categories of blue, green, yellow, and red. These results help to resolve the long-standing controversy surrounding the primacy of perception over language in the organization of hue.