Biomedical subjects

William H Swartz

Publications and source records attributed to William H Swartz.

3 recordsLinked to original sources

PubMed2005

Molecular velocity distributions and generalized scale invariance in the turbulent atmosphere.

Airborne observations of ozone, temperature and the spectral actinic photon flux for ozone in the Arctic lower stratosphere April-September 1997 and January-March 2000 allow a connection to be made between the rate of production of translationally hot atoms and molecules via ozone photodissociation and the intermittency of temperature. Seen in the context of non-equilibrium statistical mechanics literature results from molecular dynamics simulations, the observed correlation between the molecular scale production of translationally hot atoms and molecules and the macroscopic fluid mechanical intermittency of temperature may imply a departure from Maxwell-Boltzmann distributions of molecular velocities, with consequences for chemistry, radiative line shapes and turbulence in the atmosphere, arising from overpopulated high velocity tails of the probability distribution functions (PDFs).

Animals↗

PubMed2003

Outcomes, safety, and resource utilization in a collaborative care birth center program compared with traditional physician-based perinatal care.

OBJECTIVE: We compared outcomes, safety, and resource utilization in a collaborative management birth center model of perinatal care versus traditional physician-based care. METHODS: We studied 2957 low-risk, low-income women: 1808 receiving collaborative care and 1149 receiving traditional care. RESULTS: Major antepartum (adjusted risk difference [RD] = -0.5%; 95% confidence interval [CI] = -2.5, 1.5), intrapartum (adjusted RD = 0.8%; 95% CI = -2.4, 4.0), and neonatal (adjusted RD = -1.8%; 95% CI = -3.8, 0.1) complications were similar, as were neonatal intensive care unit admissions (adjusted RD = -1.3%; 95% CI = -3.8, 1.1). Collaborative care had a greater number of normal spontaneous vaginal deliveries (adjusted RD = 14.9%; 95% CI = 11.5, 18.3) and less use of epidural anesthesia (adjusted RD = -35.7%; 95% CI = -39.5, -31.8). CONCLUSIONS: For low-risk women, both scenarios result in safe outcomes for mothers and babies. However, fewer operative deliveries and medical resources were used in collaborative care.

Adult↗

PubMedDate not supplied

Impact of collaborative management and early admission in labor on method of delivery.

OBJECTIVE: This study compared the effects of early admission in labor and perinatal care provider on delivery method. Higher spontaneous vaginal delivery rates for certified nurse midwives as compared with physicians have been reported in observational studies and randomized clinical trials. Certified nurse midwives, with their more expectant approach to labor management, would be expected to admit women later in labor than obstetricians. METHODS: Prospective cohort study of 2,196 low-risk pregnancies, with singleton, vertex infants admitted in spontaneous labor. Independent and joint effects of perinatal care provider and cervical dilation at admission on delivery method were evaluated. Confounding was addressed using restriction and multiple regression. RESULTS: Fewer (23.4%) women in collaborative care were admitted in early labor (< 4 cm cervical dilation) than women managed by obstetricians (95% CI = -27.6 to -19.2). Obstetrician care had 9% to 30% fewer spontaneous vaginal deliveries. Women admitted early in labor also had 6% to 34% fewer spontaneous vaginal deliveries. Evaluation of joint effects suggested that interaction between obstetrician provider and earlier admission increased the risk of operative delivery. CONCLUSION: Later admission in labor (at 4 cm or greater cervical dilation) and management of perinatal care by certified nurse midwives in collaboration with obstetricians increased the rate of spontaneous vaginal delivery in low-risk women.

Adult↗