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variables needed to evaluate the flux terms. Consequently, the U-vector nmst be decomposed into other variables, leaving the (:-vector itself disposable. Both Williamson (2N) and vdH (2R) schemes may be easily generalized I() accommodate more than two storage registers (N or R). We make no claim that these two strategies are the only viable ones. We do suggest, however, that the vdH methodology is extremely aggressive in its conservation of computer memory usage. In t.he pursui! of computer memory use reduction, the first, casualty is the retention of the U-vector at. the beginning stage. Error control, in the more traditional sense, becomes impossible. A rejected step (such as violation of the error tolerance) cannot be restarted front U (') because with a 2N or 2t1 scheme, U (') is no tongrr available. Instead, alloting one additional register for an error estimate, one may monitor the error nlathematical soft.ware.J18, 28, 29, 58, 88] Attempts were made to solve for schemes symbolically, but il was found that the assumption of various a O = bj quickly made matters intractable because the equations of condition become algebraically nonlinear in the bi's. Scheme coefficients are given to at. lea,st 2,5 digils of accuracy. Some Ell.I{ background is necessary to facilitate a discussion on the optimization of accuracy efficiency, stability efficiency, error control reliability, step-control stability, linear stability, nonlinear stability, and dispersion and dissipation error within the context, of storage reduction in later chapters. This will be done in sections 1 and 2. Two-register schemes will be reviewed in section 3 while three-, four-, and five-register schemes will be considered in sections 4, .5, and 6. Merits of the low-storage schemes are discussed in section P (mininmm phase error), and for "P" melhods, qdisp and qdis_ are the respective dispersion and dissipation orders of accuracy.

OBJECTIVES. The level of children’s motor skill proficiency may be an important determinant of their physical activity behaviors. This study assessed the efficacy of an intervention on gross motor skill performance, physical activity, and weight status of preschoolers. METHOD. The Food Friends: Get Movin’ With Mighty Moves® program was conducted in four Head Start centers. Measurements included the Peabody Developmental Motor Scales, pedometer counts, and body mass index (BMI) z scores. RESULTS. The intervention led to significant changes in gross motor skills in the treatment group (n = 98) compared with the control group (n = 103) and was a strong predictor of overall gross motor performance (gross motor quotient), locomotor, stability, and object manipulation skills. No intervention effect was found for physical activity levels or weight status. CONCLUSION. The intervention dose was adequate for enhancing gross motor skill performance but not for increasing physical activity levels or reducing BMI.

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Oxytocin (OT) is a neuropeptide increasingly recognized for its role in bonding, socialization, and stress relief. Previous research has demonstrated participants' OT levels increased after interacting with or petting a dog, suggesting OT is at least partially responsible for the calm, relaxing feeling that participants experienced during this intervention. The purpose of our study was to more closely examine changes in oxytocin levels in men and women in response to interaction with their own dog after being separated from the dog while at work all day. This condition was compared with a reading control condition, without the presence of the dog. Because the workplace is a common stressor, participants were examined after work to evaluate how interacting with a pet may help decrease stress, as evidenced by increases in serum oxytocin levels. Ten men and ten women participated in the study. Serum oxytocin levels were obtained before the participants had contact with their dogs and then again after 25 minutes of interaction with their dog. The same protocol was followed for the reading condition except that instead of interacting with their dog, participants read nonfiction materials selected by the researchers. Serum oxytocin levels increased statistically more for women who interacted with their dog when compared with women in the reading condition (p = 0.003). There was no significant increase in oxytocin level in men after interaction with the bonded dog compared with the reading condition; in fact, male oxytocin levels decreased after both the dog and reading conditions. These results suggest that men and women may have different hormonal responses to interaction with their dogs. It is unclear to what degree OT reactivity was affected by hormones, personality traits, or interpersonal relationships; factors which warrant further research.