The Gastrointestinal Mucosa in Young Milk-Fed Calves

Gastrointestinal segments from 4 healthy, 17-, 21-, 22- and 23-day-old calves fed on whole cow’s milk were examined. Scanning electron microscopy showed that the anterior duodenum had short villi varying in shape from leaf-shaped to nodular; the middle duodenum had broad, tongue-shaped villi and the anterior, middle, and parts of the posterior jejunum had slender, finger-shaped or leaf-shaped villi. The villi of the mucosa covering Peyer’s patches in the posterior jejunum were short and either conical or tongue-shaped; there were also small “pseudovilli” caused by bulges in the lymphoid tissue. Morphometry showed that the villi were longer in the anterior jejunum than in the duodenum and the posterior parts of the jejunum (P < 0.005). Morphologically fat absorption was most heavy in the anterior third of the small intestine. Moderate amounts of fat were also found in the epithelium of the posterior jejunum and of the abomasum. Large fat droplets were seen in apical duodenal enterocytes, in contrast to the small epithelial droplets in other areas with fat absorption. Nile blue staining indicated that the fat in the large droplets was esterified.     

The Young Schoolchild's Self-Assessment in Learning Activity

The training of pupils to improve their knowledge independently is one of the key tasks of the school at the present time. It is an especially important problem in developing an active attitude on the part of pupils toward learning and in transforming the pupil into a genuine subject in learning activity. In order to be a truly independent learner, the student must learn to make a thorough and objective assessment of his/her own personal qualities and activity, i.e., it requires a certain level of development of self-assessment. Therefore, studies aimed at determining the psychological conditions and patterns of self-assessment at different developmental stages are of great importance.     

The Elaboration of Associations in Very Young Children

Iu. K. Panferov was the first to make an attempt to provide a physiological analysis of the formation of a temporary connection between a number of indifferent stimuli in school-age children (9). G.P. Zelenyi and P. A. Prokof'ev (4) published analogous studies with adult subjects.     

The Development of Young Snipe Studied by Mist-Netting

A nest record card analysis found a progressive decline in clutch size over a season, and that the larger, earlier clutches suffer higher predation. Predation levels can be linked to nest crypsis, which improves as the season advances.