ABSTRACT. The relative importance of mucoid Ps. aeruginosa, non‐mucoid Ps. aeruginosa and absence of Ps. aeruginosa as indicators of the severity of lung disease was assessed in 82 age matched children and adolescents with cystic fibrosis. Both Shwachman score and forced expiratory volume in one second (FEV1) were significantly lower in subjects whose sputa yielded mucoid strains than in those whose sputa had no Ps. aeruginosa or those with non‐mucoid forms. Furthermore 29 of 32 patients (91%) with a Shwachman score below 80 and 31 of 37 (84%) with a FEV1 of less than 75% predicted had one or more positive cultures for mucoid Ps. aeruginosa. While identification of mucoid forms of Ps. aeruginosa in the respiratory tract of children and adolescents with cystic fibrosis is an unfavourable factor, non‐mucoid forms appear to be of no major significance.

The kinetic study of the aqueous reaction, between pH 10 and 14, of eight N-(hydroxymethyl)benzamide derivatives in water at 25 degrees C, I = 1.0 M (KCl), has been performed. In all cases, the reaction proceeds via a specific-base-catalyzed deprotonation of the hydroxyl group followed by rate-limiting breakdown of the alkoxide to form aldehyde and amidate (E1cB-like). Such a mechanism was supported by the lack of general buffer catalysis and the first-order dependence of the rate of reaction at low hydroxide concentrations and the transition to zero-order dependence on hydroxide at high concentration. A rho-value of 0.67 was found for the Hammett correlation between the maximum rate for the hydroxide independent breakdown of the deprotonated carbinolamide (k1) and the substituent on the aromatic ring of the title compounds. Conversely, the substituents on the aromatic ring of the amide portion of the carbinolamide had only a small effect on the Ka of the hydroxyl group indicating that the amide group does not strongly transmit the electronic information of the substituents. These observations led to the conclusion that the major effect of electronic changes on the amide of carbinolamides is reflected in the nucleofugality of the amidate once the alkoxide is formed and not in the pKa of the hydroxyl group of the carbinolamide.

North America has distinct types of Hyphantria moths (Arctiidae) characterized by red (RD)‐ and black (BL)‐headed larvae, of which the taxonomic status is unresolved. Genetic divergence of 26 populations, based on 710 bp of the mtCOI sequence, showed two phylogenetic lineages, which could not be connected in the haplotype network with 95% confidence. The two lineages are separated by 3.1% sequence divergence and should be considered for full species status. The estimated split occurred 1.2–1.6 million years ago. The range of the RD type covered most of the continent, whereas that of the BL type was limited to eastern deciduous forests. Several biological characteristics were differentiated in the zone of cohabitation where BL had more annual generations than RD. Spring emergence of BL precedes that of RD in the field by at least 1 month, because the diapause in BL was shallow, whereas it was deep in RD. Voltinism requires discreteness of numbers, which functions as a sink of hybrids between the two parental lines that have distinct but equally adaptive reproductive strategies; BL may be more r‐strategist‐like and RD more K‐strategist‐like, because fast‐developing BL has multivoltine life cycle, investing less silk proteins as the round‐the‐clock feeder, and slow‐developing RD univoltine one investing more silk as the nocturnal feeder. Also, intensity of diapause, deep in RD and weak in BL, was grossly different, which may enforce segregation of spring adults. Allochronic speciation avoiding coincidental occurrence of adult stages is therefore the most likely scenario. Because the adults never meet in nature, large morphological differentiation is not required.

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Abstract-The tolerance of four aquatic organisms to four chemicals (aldicarb, dimethoate, imidacloprid, and tebufenozide) was determined using 48-h acute toxicity tests at 27ЊC. Species included two saline (Artemia sp. and Aedes taeniorhynchus (Wiedemann)) and two freshwater (Daphnia magna Straus and Aedes aegypti (L.)) organisms. Temperature was also evaluated as a toxicity modifying factor for the freshwater species. Two selective insecticides (imidacloprid and tebufenozide) were compared with two broad-spectrum insecticides, aldicarb and dimethoate. In general, A. taeniorhynchus was the most susceptible, and Artemia sp. was the most tolerant to insecticides used under our experimental conditions. Both aldicarb and dimethoate caused neurotoxicity in all organisms tested. Mortality associated with molting suggested that tebufenozide affected the molting process of all organisms, causing the formation of an incompletely sclerotized head capsule and the failure of ecdysis in the mosquito species. These responses resulted in lethal larval molts. Imidacloprid, on the other hand, caused delayed symptoms of general nerve poisoning compared with the two acetylcholine esterase inhibitors. Our results suggest that both tebufenozide and imidacloprid would be selective insecticides that can be used with reasonable environmental safety toward nontarget aquatic crustaceans. There was a greater correlation of susceptibility to test chemicals within taxonomically close organisms than between organisms that share habitats.

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The tolerance of four aquatic organisms to four chemicals (aldicarb, dimethoate, imidacloprid, and tebufenozide) was determined using 48‐h acute toxicity tests at 27°C. Species included two saline (Artemia sp. and Aedes taeniorhynchus (Wiedemann)) and two freshwater (Daphnia magna Straus and Aedes aegypti (L.)) organisms. Temperature was also evaluated as a toxicity modifying factor for the freshwater species. Two selective insecticides (imidacloprid and tebufenozide) were compared with two broad‐spectrum insecticides, aldicarb and dimethoate. In general, A. taeniorhynchus was the most susceptible, and Artemia sp. was the most tolerant to insecticides used under our experimental conditions. Both aldicarb and dimethoate caused neurotoxicity in all organisms tested. Mortality associated with molting suggested that tebufenozide affected the molting process of all organisms, causing the formation of an incompletely sclerotized head capsule and the failure of ecdysis in the mosquito species. These responses resulted in lethal larval molts. Imidacloprid, on the other hand, caused delayed symptoms of general nerve poisoning compared with the two acetylcholine esterase inhibitors. Our results suggest that both tebufenozide and imidacloprid would be selective insecticides that can be used with reasonable environmental safety toward nontarget aquatic crustaceans. There was a greater correlation of susceptibility to test chemicals within taxonomically close organisms than between organisms that share habitats.