Regulation of lymphokine production in peripheral blood mononuclear cell cultures

An increase in the production of macrophage migration inhibitory factor, chemotactic factor for neutrophils, and skin reactive factor, was observed in lymphocyte cultures if the cells were allowed to age in culture for 24 h. The increased lymphokine production was reduced by adding concanavalin A-stimulated and mitomycin C-treated suppressor cells. It is suggested that the lymphokine production could be regulated by suppressive mononuclear cells.     

The effect of kryptopyrrole on the porphyrin auxotrophic strains ofBacillus subtilis

Zusammenfassung Nachweis, dass Kryptopyrrol zwar die Porphyrinsynthese inBacillus subtilis Wildtyp stimuliert, nicht aber das Wachstum von Porphyrin-Mangelmutanten dieses Bakteriums ermöglichen kann.     

Effect of theophylline and triiodothyronine on some early estrogenic responses in the rat uterus

Theophylline increases and triodothyronine decreases uterine edema induced by physiological doses of estradiol-17 beta. Both of them decrease estrogen-induced uterine eosinophilia and the number of blood eosinophils, suggesting an explanation for the results in the uterus.     

Karyotypic races of the common shrew (Sorex araneus L.) from northern Poland

Karyotypic races of the common shrew which differed with respect to the combinations of chromosome arms in certain 2-armed autosomes were distinguished in Poland. Two eastern races with the arm combination ik, and one western race with the arm combination hi in the third pair of autosomes were established. In the contact area of these chromosomal forms, the fourth karyotypic race with the arm combination hk was found.     

Participatory Design and Technologies for Sustainable Development: an Approach from Action Research

This paper explores the relevance of the action research for design of technological solutions that lead to both systemic sustainable development and active involvement of the community. The paper shows how this idea was implemented in a project for water resource conservation with educational institutions of rural areas in Colombia. Through the use of technology, a reduction in water consumption increases in awareness about the use of this natural resource, and the active involvement of the community were sought. Additionally, social processes related to the conservation of natural resources were addressed through a socio-technical approach for analysis and design. During the application of the Soft Systems Methodology (SSM), the participants and researchers created technological prototypes that allowed to: 1) give visibility to the community’s initiatives, and 2) save water in the households. This paper focuses on the importance of the design process of innovative solutions for social and environmental issues through the participative approach of action research.

     

Studies on the reconstitution ofP. clarkii blue carotenoprotein from its isolated subunits

Summary A blue carotenoid-protein complex (_max 635 nm) was extracted and purified from the carapace of the crayfishProcambarus clarkii. The complex was further liberated from astaxanthin, its prostetic group, causing dissociation into apoprotein subunits. Reconstitution of the complex from the various sub-units (isolated by chromatofocusing) plus astaxanthin was attempted. Apoprotein-size pigments of rose-purple color (_max 545 nm) were obtained. It was found that both monomers are required in order to a blue complex fairly similar in structure ot the native one. However, the native conformation was not completely recovered, as indicated by some differences in the UV spectrum.     

Controllability of complex networks

The ultimate proof of our understanding of natural or technological systems is reflected in our ability to control them. Although control theory offers mathematical tools for steering engineered and natural systems towards a desired state, a framework to control complex self-organized systems is lacking. Here we develop analytical tools to study the controllability of an arbitrary complex directed network, identifying the set of driver nodes with time-dependent control that can guide the system's entire dynamics. We apply these tools to several real networks, finding that the number of driver nodes is determined mainly by the network's degree distribution. We show that sparse inhomogeneous networks, which emerge in many real complex systems, are the most difficult to control, but that dense and homogeneous networks can be controlled using a few driver nodes. Counterintuitively, we find that in both model and real systems the driver nodes tend to avoid the high-degree nodes.