Some difficulties of ecological thinking,considered from a critical systems perspective: A plea for critical holism

We probably have simplified matters too much. We tend to talk about systems thinking and practice as if we knew what they are. The fashionable call for “holistic” or “systems” thinking in ecological issues provides a major example. This much is certain: the quest for comprehensiveness, although it represents an epistemologically necessary idea, is not realizable. If we assume that it is realizable, the critical idea underlying the quest will be perverted into its opposite, i.e., into a false pretension to superior knowledge and understanding—a danger of which the environmental movement does not always appear to be sufficiently aware. My question, therefore, is this: How can we deal critically with the fact that our thinking, and hence our knowledge, designs, and actions, cannot possibly be comprehensive, in the sense that we never “comprehend” all that ought to be understood before we pass to judgment and action? What consequences does this fact imply for a critical systems approach to ecological concerns and, ultimately, for our concepts of rationality in general?     

Evaluation of oral vaccination against mouse-typhoid in a new animal model

Summary In a simple, new animal model the spread of mouse-typhoid within a mouse-colony was studied and oral vaccination against this disease was evaluated. Live vaccine was superior to inactivated vaccine.     

Freisetzung von Kalium aus denerviertem und innerviertem Skelettmuskel durch Acetylcholin

Summary Both hind limbs of cats (one being normally innervated, the other 8–12 days after denervation) were perfused and the quantities of potassium liberated from the two limbs in response to intraarterial injections of varying amounts of acetylcholine were compared by collecting the venous outflow from both sides separately; considerably larger quantities of potassium were found to be liberated from the denervated than from the innervated muscle after equal doses of ACH; the threshold dose of ACH for eliciting a measurable liberation of potassium being much lower on the denervated side. The dose response relation between injected ACH and potassium-liberation is of a different nature for innervated and denervated muscle. The results obtained are compatible with expectations derived from the short circuit theory of the transmitter action on the neuromuscular endplate (Fatt andKatz). The reasons of the difference in the dose relations for the innervated and denervated muscle are discussed.     

The effect of BCG-vaccination on vaccinia virus infections in mice

Summary Pretreatment with BCG yielded a high degree of protection against experimental vaccinia virus infections in mice.Corynebacterium parvum andAristolochia acid were less protective; other immunostimulants were ineffective.     

Immunostimulating and adjuvant activities of a low molecular weight lipopeptide]

From crude extracts of a Streptomyces strain exhibiting immunopotentiating effects, a tetrapeptide was isolated and its structure established as L Ala leads to D isoGlu leads to L, L Dap comes from Gly. This peptide was devoid of biological activity but its chemical coupling with lauric acid gave a substance endowed with adjuvant and immunostimulating properties. This substance and the corresponding synthetic lauroyltetrapeptide were as active in this respect as the muramyl-dipeptide, thus far considered as the minimal adjuvant-active structure of bacterial cell walls: the presence of a sugar moiety is therefore not a prerequisite for immunopotentiating activities.     

Suppression and enhancement of humoral immune response to Toxoplasma gondii by passive antibody

Anti-toxoplasma antibodies administered passively to mice may lead to suppression of enhancement (reported for the first time with Protozoan parasites) of subsequent antibody response when these animals are later infected with Toxoplasma gondii. The outcome is dependent on infecting strain of Toxoplasma and the antigen-antibody ratio.     

Identification of a cold receptor reveals a general role for TRP channels in thermosensation

The cellular and molecular mechanisms that enable us to sense cold are not well understood. Insights into this process have come from the use of pharmacological agents, such as menthol, that elicit a cooling sensation. Here we have characterized and cloned a menthol receptor from trigeminal sensory neurons that is also activated by thermal stimuli in the cool to cold range. This cold- and menthol-sensitive receptor, CMR1, is a member of the TRP family of excitatory ion channels, and we propose that it functions as a transducer of cold stimuli in the somatosensory system. These findings, together with our previous identification of the heat-sensitive channels VR1 and VRL-1, demonstrate that TRP channels detect temperatures over a wide range and are the principal sensors of thermal stimuli in the mammalian peripheral nervous system.