Procedural and declarative knowledge: an evolutionary perspective

It appears that there are resemblances in the organization of memory and the visual system, although the functions of these faculties differ considerably. In this article, the principles behind this organization are discussed. One important principle regards the distinction between declarative and procedural knowledge, between knowing that and knowing how. Declarative knowledge is considered here not as an alternative kind of knowledge, as is usually the case in theories of memory, but as part of procedural knowledge. In our view this leads to another approach with respect to the distinction. Declarative knowledge has occupied more attention in (cognitive) psychological research than can be justified on the basis of the importance of procedural knowledge for behavior. We also discuss the question whether there are other brain faculties that reflect the same organizational characteristics. We conclude with some speculations about the consequent role of consciousness in such a tentative model

Pregnancy diagnosis using bovine pregnancy-associated glycoprotein in purebred beef heifers mated at a first or second synchronised oestrus.

editorial reviewe

Half-life of serum bovine pregnancy-associated glycoprotein (bPAG), post-partum anoestrus and performance of beef cows.

editorial reviewe

Post-Partum decline in serum pregnancy-associated glycoprotein (bPAG) in four breeds of cattle under different nutritional regimes.

editorial reviewe

Methods for estimating types of soil organic carbon and their application to surveys of UK urban areas

The occurrence of substantial quantities of black carbon (BC) in urban soil due to local dispersal following incomplete combustion of fossil fuel complicates the determination of labile soil organic carbon (SOC). Estimates of SOC content were made from loss on ignition (LOI) analyses undertaken on samples (0–15 cm depth) from comprehensive soil geochemical surveys of three UK urban areas. We randomly selected 10 samples from each decile of the LOI distribution for each of the surveys of Coventry (n = 808), Stoke-on-Trent (n = 737) and Glasgow (n = 1382) to investigate the proportions of labile SOC and BC. We determined their total organic carbon (TOC) and BC contents, and by difference the labile SOC content, and investigated the linear relationship of the latter with SOC estimates based on LOI analyses. There was no evidence for a difference in the slope of the regression for the three urban areas. We then used a linear regression of labile SOC based on LOI analyses (r2 = 0.81) to predict labile SOC for all survey samples from the three urban areas. We attribute the significantly higher median BC concentrations in Glasgow (1.77%, compared with 0.46 and 0.59% in Coventry and Stoke-on-Trent) to greater dispersal of coal ash across the former. An analysis of the 30 samples showed that LOI at 450 C accounts for a consistent proportion of BC in each sample (r2 = 0.97). Differences between TOC (combustion at 1050 C after removal of inorganic carbon) and an LOI estimate of SOC may be a cost-effective method for estimation of BC. Previous approaches to estimation of urban SOC contents based on half the mean SOC content of the equivalent associations under pasture, underestimate the empirical mean value