5 resultados para Timing
em Digital Commons at Florida International University
Resumo:
This study investigates the relationship between adoption timing of Statement of Financial Accounting Standards 87 and earnings management after adoption. Earnings management, defined consistent with Schipper (1989), is tested through hypotheses using (1) a portfolio approach and (2) pension rates. One Hypothesis uses a Modified Jones (1991) Model as a proxy for discretionary accruals and the other uses pension rate estimates.^ Statistically significant relationships are found between adoption timing and (1) discretionary accruals and (2) estimated rate-of-return (ROR) on pension plan assets. Early adopting firms tend to have lower discretionary accruals after adoption than on-time adopters. They also tend to use higher ROR estimates which are not supported by higher actual returns. Thus, while early adopters may be using ROR to manage income, this tends to not result in higher discretionary accruals. ^
Resumo:
This study investigated the effects of augmented prenatal auditory stimulation on postnatal visual responsivity and neural organization in bobwhite quail (Colinus virginianus). I delivered conspecific embryonic vocalizations before, during, or after the development of a multisensory, midbrain audiovisual area, the optic tectum. Postnatal simultaneous choice tests revealed that hatchlings receiving augmented auditory stimulation during optic tectum development as embryos failed to show species-typical visual preferences for a conspecific maternal hen 72 hours after hatching. Auditory simultaneous choice tests showed no hatchlings had deficits in auditory function in any of the groups, indicating deficits were specific to visual function. ZENK protein expression confirmed differences in the amount of neural plasticity in multiple neuroanatomical regions of birds receiving stimulation during optic tecturn development, compared to unmanipulated birds. The results of these experiments support the notion that the timing of augmented prenatal auditory stimulation relative to optic tectum development can impact postnatal perceptual organization in an enduring way.^
Resumo:
This research first evaluated the effects of urban wildland interface on reproductive biology of the Big Pine Partridge Pea, Chamaecrista keyensis, an understory herb that is endemic to Big Pine Key, Florida. I found that C. keyensis was self-compatible, but depended on bees for seed set. Furthermore, individuals of C. keyensis in urban habitats suffered higher seed predation and therefore set fewer seeds than forest interior plants. ^ I then focused on the effects of fire at different times of the year, summer (wet) and winter (dry), on the population dynamics and population viability of C. keyensis. I found that C. keyensis population recovered faster after winter burns and early summer burns (May–June) than after late summer burns (July–September) due to better survival and seedling recruitment following former fires. Fire intensity had positive effects on reproduction of C. keyensis. In contrast, no significant fire intensity effects were found on survival, growth, and seedling recruitment. This indicated that better survival and seedling recruitment following winter and early summer burns (compared with late summer burns) were due to the reproductive phenology of the plant in relation to fires rather than differences in fire intensity. Deterministic population modeling showed that time since fire significantly affected the finite population growth rates (λ). Particularly, recently burned plots had the largest λ. In addition, effects of timing of fires on λ were most pronounced the year of burn, but not the subsequent years. The elasticity analyses suggested that maximizing survival is an effective way to minimize the reduction in finite population growth rate the year of burn. Early summer fires or dry-season fires may achieve this objective. Finally, stochastic simulations indicated that the C. keyensis population had lower extinction risk and population decline probability if burned in the winter than in the late summer. A fire frequency of approximately 7 years would create the lowest extinction probability for C. keyensis. A fire management regime including a wide range of burning seasons may be essential for the continued existence of C. keyensis and other endemic species of pine rockland on Big Pine Key. ^
Resumo:
The optimization of the timing parameters of traffic signals provides for efficient operation of traffic along a signalized transportation system. Optimization tools with macroscopic simulation models have been used to determine optimal timing plans. These plans have been, in some cases, evaluated and fine tuned using microscopic simulation tools. A number of studies show inconsistencies between optimization tool results based on macroscopic simulation and the results obtained from microscopic simulation. No attempts have been made to determine the reason behind these inconsistencies. This research investigates whether adjusting the parameters of macroscopic simulation models to correspond to the calibrated microscopic simulation model parameters can reduce said inconsistencies. The adjusted parameters include platoon dispersion model parameters, saturation flow rates, and cruise speeds. The results from this work show that adjusting cruise speeds and saturation flow rates can have significant impacts on improving the optimization/macroscopic simulation results as assessed by microscopic simulation models.
Resumo:
Empirical research has shown that pubertal development is closely linked with adolescent externalizing (e.g., aggressive) and internalizing (e.g., anxiety) problems. In most studies, pubertal timing, pubertal status, or both, are used to examine this link. The present study adds to the existing literature by examining the link between puberty and adolescent behavior problems in a sample of predominantly urban African American adolescent girls. One hundred and seventeen adolescent girls of color, aged 11-18 (M = 14.72 SD = 1.44), and their primary caregiver participated in this study. Sixty-eight percent were African American, 22.2 % were Hispanic/Latina, and 9.4% were Haitian. Among the Hispanic/Latina girls, 9.4% were Black Hispanic/Latina. Results showed that pubertal status and perceived pubertal timing (breasts) are better predictors of externalizing behavior problems than chronological age and quality of relationship with peers. No significant findings were found with anxious/depressed symptoms.