Cognitive constraints influence an understanding of life-cycle change.

We investigated children's (n = 120; 3- to 11-year-olds) and adults' (n = 18) reasoning about life-cycle changes in biological organisms by examining their endorsements of four different patterns of life-span changes. Participants were presented with two separate tasks: (a) judging possible adult versions of a juvenile animal and (b) judging possible juvenile versions of an adult animal. The stimuli enabled us to examine the endorsement of four different patterns of change: identical growth, natural growth, dramatic change, and speciation.

Bacteraemic urinary tract infection: management and outcomes in young infants.

Objectives: To determine predictors of parenteral antibiotic duration and the association between parenteral treatment duration and relapses in infants <3 months with bacteraemic urinary tract infection (UTI).

Design: Multicentre retrospective cohort study.

Setting: Eleven healthcare institutions across the USA.

Blood culture time to positivity in febrile infants with bacteremia.

Importance: Blood cultures are often obtained as part of the evaluation of infants with fever and these infants are typically observed until their cultures are determined to have no growth. However, the time to positivity of blood culture results in this population is not known.

Objective: To determine the time to positivity of blood culture results in febrile infants admitted to a general inpatient unit.

Genetic analysis of a novel Xylella fastidiosa subspecies found in the southwestern United States.

Xylella fastidiosa, the causal agent of several scorch diseases, is associated with leaf scorch symptoms in Chitalpa tashkentensis, a common ornamental landscape plant used throughout the southwestern United States. For a number of years, many chitalpa trees in southern New Mexico and Arizona exhibited leaf scorch symptoms, and the results from a regional survey show that chitalpa trees from New Mexico, Arizona, and California are frequently infected with X. fastidiosa.