A distinctive type of luminescent system present in the large dorsal luminous organ of the oceanic squid Symplectoteuthis oualaniensis is described. The organ produces an intense blue flash of light followed by a rapid decay in light intensity. Luminescence originates from numerous oval granules present in the luminous organ. The essential light-emitting components are membrane bound. Intact gr...

Sendai virus is able to induce the fusion of human erythrocytes. Bivalent cations or ATP are not essential for polyerythrocyte formation. High fusion indices were obtained when Sendai virus was added to cells incubated in the presence of both EDTA and iodoacetic acid. Human erythrocyte ghosts prepared by gradual hemolysis still retain the potential to undergo virus-induced fusion. Fusion of hum...

cations is also difficult to test, as their presence is essential for the interaction of phytohaemagglutinin with its membrane receptors (Kay, 1971 ; Lindahl-Kiessling, 1972). The observation that the Caz+ ionophore A231 87 is itself a lymphocyte mitogen (Maino et al., 1974) lends strong support to the hypothesis that the rate of CaZ+ uptake may be of crucial importance, but the results present...

Articular cartilage is a unique load-bearing connective tissue with a low intrinsic capacity for repair and regeneration. Its avascularity makes it relatively hypoxic and its unique extracellular matrix is enriched with cations, which increases the interstitial fluid osmolarity. Several physicochemical and biomechanical stimuli are reported to influence chondrocyte metabolism and may be utilize...

This paper formalizes the notion of justiied plans, which captures the intuition behind \good" plans. A justiied plan is one that does not contain operators which are not necessary for achieving a goal. The importance of formalizing this notion is due to two reasons. First, it gives rise to methods for optimizing a given plan by removing \useless" operators. Second, several important concepts d...

The interface speci cation of a procedure describes the procedure s behavior using pre and postconditions These pre and postconditions are written using various functions If some of these functions are partial or underspeci ed then the procedure speci cation may not be well de ned We show how to write pre and postcondition speci cations that avoid such problems by having the precondition protec...

H, K, Rb, and Li inhibit Na-dependent alanine influx across the brush border of rabbit ileum. Kinetic analysis indicates that H and K behave as competitive inhibitors of influx so that increasing the concentration of H or K in the mucosal solution is kinetically indistinguishable from decreasing the Na concentration. In addition the coupling between alanine and Na influxes is markedly reduced a...

Recent studies of nuclear spin polarization effects in cyclopropane derivatives have provided considerable information on the structure as well as the spin and charge density distributions in this class of radical ca,tions. In the present work we report an extension of the frontier MO/perturbation MO theory of homoconjugation to include such species in an attempt to rationalize further the expe...

Ten semi-synthetic analogs of A23187 (calcimycin), with only the benzoxazole ring substituents modified together with the ionophore X14885A were studied with regard to their calcium and magnesium carrier properties through an organic phase (toluene - butanol, 70:30). The results indicate that the carboxylic group and the oxazolic nitrogen, maintained in the ortho position are essential for the ...

The cyclization of cyclohexane-1,3-diones with various substituted pyridinium salts afforded functionalized 8-oxa-10-aza-tricyclo[7.3.1.0(2,7)]trideca-2(7),11-dienes. The reaction proceeds by regioselective attack of the central carbon atom of the 1,3-dicarbonyl unit to 4-position of the pyridinium salt and subsequent cyclization by base-assisted proton migration and nucleophilic addition of th...