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We have observed a sample of $\delta$ Scuti stars discovered by the ROTSE collaboration in 1999 with Super-LOTIS in order to characterize changes in their pulsation periods over a time baseline of roughly three years. Achieving these goals required the creation of an automated astrometric and photometric data reduction pipeline for the Super-LOTIS camera. Applying this pipeline to data from a June 2002 observing campaign, we detect pulsations in 18 objects, and find that in two cases the periods have changed significantly over the three years between the ROTSE and Super-LOTIS observations. Since theory predicts that evolutionary period changes should be quite small, sources of non-evolutionary period changes due to the interactions of pulsations modes are discussed.

The sloshing problem is a linear eigenvalue problem for a partial differential operator that describes the small lateral oscillations of the free surface of an ideal fluid on a container subject to gravity. We consider two-dimensional problems on regions representing the cross-section of a cylindrical tank or canal. A conformal mapping transforms the sloshing problem on the given region to a weighted eigenvalue problem on a simple region such as a rectangle. The weighted problem can be treated very effectively by the powerful methods of intermediate problems. The strength and versatility of the method is illustrated with a variety of examples.

Previous authors have shown that adverse changes in cerebral blood flow are reflected in changes in ICP. We sought to determine whether increased Paw required to ventilate newborns may alter ICP and predispose them to intraventricular hemorrhage.14 ill infants were studied. All infants were ventilated with Bird ventilators and Paw was measured using the Bird mean Airway Pressure Monitor. ICP was measured using a Ladd ICP monitor with fiberoptic sensor secured over the anterior fontanel. Mean blood pressures were recorded via aortic catheters.The study was commenced at institution of assisted ventilation. Most common beginning settings included PEEP 4, PIP 25, F102 100%. One hour later, stepwise changes were made in PEEP/PIP to produce increments of 1-2 cm H2O Paw pressure. Increases were made to achieve maximum settings of PEEP 12 and Paw 22. Resulting ICP varied only from 4-9 cm H2O. No values approached the 18-20 cm H2O value which is considered abnormal. Blood pressure did not change during the study.We conclude that in nonhypoxic infants with stable blood pressures occasional high mean airway pressures do not adversely affect ICP.