Search strategies used by APP transgenic mice during navigation in the Morris water maze

TgCRND8 mice represent a transgenic mouse model of Alzheimer's disease, with onset of cognitive impairment and increasing amyloid-beta plaques in their brains at 12 weeks of age. In this study, the spatial memory in 25- to 30-week-old TgCRND8 mice was analyzed in two reference and one working memory Morris water maze (MWM) tests. In reference memory tests, the mice were trained to escape to a hidden platform, which in one version of the test was marked by a visual cue. In the working memory test, the hidden platform was moved daily to different locations. The TgCRND8 mice were impaired in reference memory when trained in a hidden platform test. However, the mice developed spatial memory comparable to non-Tg littermates in a cued reference memory test. The mice showed also an impairment in spatial working memory. Analysis of search paths revealed that in contrast to non-Tg littermates, TgCRND8 mice did not use spatial strategies during their navigation. Instead, they learned to locate an escape platform using a nonspatial, chaining strategy. The study showed that (1) the impairment in the reference memory of TgCRND8 mice was reduced when a hidden platform was cued, and that (2) both working and reference memory systems of TgCRND8 mice, but not (3) the plasticity of choice between search strategies, are compromised by the transgene-induced pathology.     

The Danish Biofuel Debate: Coupling Scientific and Politico-Economic Claims

What role does scientific claims-making play in the worldwide promotion of biofuels for transport, which continues despite serious concerns about its potentially adverse social and environmental effects? And how do actors with very different and conflicting viewpoints on the benefits and drawbacks of biofuels enrol scientific authority to support their positions? The sociological theory of functional differentiation combined with the concept of advocacy coalition can help in exploring this relationship between scientific claims-making and the policy stance of different actors in public debates about biofuels. In Denmark two distinct scientific perspectives about biofuels map onto the policy debates through articulation by two competing advocacy coalitions. One is a reductionist biorefinery perspective originating in biochemistry and neighbouring disciplines. This perspective works upwards from the molecular level and envisions positive synergies in the use of biomass. The other is a holistic bioscarcity perspective originating in life-cycle analysis and ecology. This perspective works downwards from global resource scope conditions, and envisions negative consequences from an increased reliance on biomass. Understanding how these scientific perspectives and policy stances are coupled sheds light on three contentious policy questions: how Denmark should include biomass in its energy provision, what role Denmark might play in the global development of biofuels and what kind of subsidy schemes should be implemented.     

The development of olfactory preferences for artificial odors briefly experienced by the precocial spiny mouse young

Groups of pups, aged 2, 4, 6, 12, 16, and 18 days of the precocial murid rodent spiny mouse (Acomys cahirinus), were each exposed for 1.5 h to one of the experimental odors, cinnamon or cumin, present in the surrounding environment. The odors were not contingent upon home-cage odors or any other reinforcers. This simple exposure produced a strong preference for the exposed odor in multichoice preference tests carried out 48 h after the exposure in pups from groups aged 2 through 16 days. Older pups exposed to cinnamon or cumin at Day 18 did not show a significant preference for the familiar odor. Both experimental odors used were found to be neutral for control experimentally naive pups within a tested age span. These results point at a stimulus familiarity, rather than associative learning in the development of olfactory preferences in young spiny mouse pups.     

Adoption Counseling as a Professional Specialty Area for Counselors

Adoption is an area of professional specialization that has resided primarily with social workers. However, with some additional training, many counselors can acquire the expertise to provide service to members of the adoption triad: birthparents, adoptive parents, and adoptees. This article provides an overview of the major issues that may arise in the lives of triad members and suggests ways in which counselors can be equipped to respond to those issues.     

Colour matching of isoluminant samples and backgrounds: a model

A cone-opponent-based vector model is used to derive the activity in the red-green, yellow-blue, and achromatic channels during a sequential asymmetric colour-matching experiment. Forty Munsell samples, simulated under illuminant C, were matched with their appearance under eight test illuminants. The test samples and backgrounds were photometrically isoluminant with each other. According to the model, the orthogonality of the channels is revealed when test illuminants lie along either red-green or yellow blue cardinal axes. The red green and yellow-blue outputs of the channels are described in terms of the hue of the sample. The fact that the three-channel model explains the data in a colour-matching experiment indicates that an early form of colour processing is mediated at a site where the three channels converge, probably the input layer of V1.