The Concept of Developmental-Tasks and its Significance for Education and Social Work

The term "developmental-task" was introduced by Robert Havighurst in the 1950's. According to R. Harvighurst, the term refers to tasks which arise in a social context during an individual lifetime. Since the 1950's the concept of developmental-tasks has become an important theoretical approach in educational science and in theories of growth and development - but not in social work and social pedagogy. In the following article I aim to show that this approach is very important to theory and practice of social pedagogy and social work.

Dilution and redistribution effects of rapid 2-litre infusions of 0.9% (w/v) saline and 5% (w/v) dextrose on haematological parameters and serum biochemistry in normal subjects: a double-blind crossover study

Although hypoalbuminaemia after injury may result from increased vascular permeability, dilution secondary to crystalloid infusions may contribute significantly. In this double-blind crossover study, the effects of bolus infusions of crystalloids on serum albumin, haematocrit, serum and urinary biochemistry and bioelectrical impedance analysis were measured in healthy subjects. Ten male volunteers received 2-litre infusions of 0.9% (w/v) saline or 5% (w/v) dextrose over 1 h; infusions were carried out on separate occasions, in random order. Weight, haemoglobin, serum albumin, serum and urinary biochemistry and bioelectrical impedance were measured pre-infusion and hourly for 6 h. The serum albumin concentration fell in all subjects (20% after saline; 16% after dextrose) by more than could be explained by dilution alone. This fall lasted more than 6 h after saline infusion, but values had returned to baseline 1 h after the end of the dextrose infusion. Changes in haematocrit and haemoglobin were less pronounced (7.5% after saline; 6.5% after dextrose). Whereas all the water from dextrose was excreted by 2 h after completion of the infusion, only one-third of the sodium and water from the saline had been excreted by 6 h, explaining its persistent diluting effect. Impedances rose after dextrose and fell after saline (P<0.001). Subjects voided more urine (means 1663 and 563 ml respectively) of lower osmolality (means 129 and 630 mOsm/kg respectively) and sodium content (means 26 and 95 mmol respectively) after dextrose than after saline (P<0.001). While an excess water load is excreted rapidly, an excess sodium load is excreted very slowly, even in normal subjects, and causes persistent dilution of haematocrit and serum albumin. The greater than expected change in serum albumin concentration when compared with that of haemoglobin suggests that, while dilution is responsible for the latter, redistribution also has a role in the former. Changes in bioelectrical impedance may reflect the electrolyte content rather than the volume of the infusate, and may be unreliable for clinical purposes.

Control concept for autonomous changeable material flow systems

Today’s material flow systems for mass customization or dynamic productions are usually realized with manual transportation systems. However new concepts in the domain of material flow and device control like function-oriented modularization and intelligent multi-agent-systems offer the possibility to employ changeable and automated material flow systems in dynamic production structures. These systems need the ability to react on unplanned and unexpected events autonomously.

Promoting a functional physical self-concept in physical education: Evaluation of a 10-week intervention

Most physical education intervention studies on the positive effect of sports on self-concept development have attempted to increase schoolchildren’s self-concept without taking the veridicality of the self-concept into account. The present study investigated whether a 10-week intervention in physical education would lead to an increase not only in the general level of self-concept of endurance and self-concept of strength but also in its veridicality in those who had previously under- or overestimated their abilities. A total of 464 primary schoolchildren (246 boys, 218 girls, Mage = 11.9) either participated in the intervention or served as controls. The intervention group received endurance and strength training during physical education lessons carried out with a consistent individualized teacher frame of reference (iTFR). Results showed that this specific intervention was associated with increases not only in the general level of self-concept but also in its veridicality in under- and overestimators. Results are discussed in terms of didactic methods to promote functional self-concepts in physical education.