Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Hidradenite Supurativa/tratamento farmacológico , Interleucina-17/antagonistas & inibidores , Qualidade de Vida , Adulto , Anticorpos Monoclonais Humanizados/efeitos adversos , Feminino , Hidradenite Supurativa/complicações , Hidradenite Supurativa/diagnóstico , Hidradenite Supurativa/imunologia , Humanos , Injeções Subcutâneas , Interleucina-17/imunologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Índice de Gravidade de Doença , Resultado do TratamentoAssuntos
Arvicolinae , Comportamento Alimentar , Roedores , Animais , Feminino , Masculino , MassachusettsRESUMO
Pigeons were presented with multiple schedules of alternating 90-sec components. When components in which grain was never presented alternated with components in which grain was presented on a variable-interval schedule, the average rate of responding in the variable-interval components increased, showing overall positive behavioral contrast. Unlike previous reports, this study found that the response rates for all birds increased toward the end of the variable-interval components as training proceeded. This increase in local response rate disappeared when the multiple schedule was composed solely of variable-interval components and reappeared when the variable-interval components were again alternated with extinction. This finding cannot be predicted or explained by recent theories of behavioral contrast based on autoshaping, and thus questions their sufficiency. We suggest that this local response-rate increase results from the predictable change from high to low density of reinforcement at the end of the fixed-duration component. Thus, the present effect apparently illustrates a different type of interaction between components of a multiple schedule than that described by previous theories of contrast. In a given procedure, either or both types of interaction may occur; neither provides a complete account of behavioral contrast.
RESUMO
The rate of cell division decreases as tobacco leaves grow, and older leaves grow without any cell divisions. Disks were cut from leaves having differing degrees of cell division at various developmental stages. In the chlorenchy, induced susceptibility to photodestruction of chloroplasts was used to measure sensitivity to gamma radiation as a function of the rate of cell division. The same biological effect can thereby be studied both in dividing and in nondividing tissues of the same morphological and physiological cell types. The radiosensitivities were approximately the same, irrespective of the extent of cell divisions.
