Donald R. Matthews to Professor Silver, 26 March 1963

Professional correspondenc

Vaccinating to Prevent Pneumonia

Bovine Respiratory Disease (BRD) is a major problem for cattle and it continues to cause serious economic losses. Pneumonia is its most serious form. BRD causes increased death losses, higher medication and labor costs, and lost production. It occurs most commonly within a few weeks of weaning and is especially troublesome then. BRD is more serious in calves which are shipped long distances right after weaning and is often referred to as shipping fever

Ocean Rossby waves as a triggering mechanism for primary Madden-Julian events

The Madden–Julian Oscillation (MJO) is sporadic, with episodes of cyclical activity interspersed with inactive periods. However, it remains unclear what may trigger a Madden–Julian (MJ) event which is not immediately preceded by any MJO activity: a ‘primary’ MJ event. A combination of case-studies and composite analysis is used to examine the extent to which the triggering of primary MJ events might occur in response to ocean dynamics. The case-studies show that such events can be triggered by the arrival of a downwelling oceanic equatorial Rossby wave, which is shown to be associated with a deepening of the mixed layer and positive sea-surface temperature (SST) anomalies of the order of 0.5–1 °C. These SST anomalies are not attributable to forcing by surface fluxes which are weak for the case-studies analysed. Furthermore, composite analysis suggests that such forcing is consistently important for triggering primary events. The relationship is much weaker for successive events, due to the many other triggering mechanisms which operate during periods of cyclical MJO activity. This oceanic feedback mechanism is a viable explanation for the sporadic and broadband nature of the MJO. Additionally, it provides hope for forecasting MJ events during periods of inactivity, when MJO forecasts generally exhibit low skill

A dynamical ocean feedback mechanism for the Madden-Julian Oscillation

Composite analysis is applied to study the dynamical ocean response to Madden-Julian (MJ) events, measured by anomalies in sea surface height from the merged TOPEX/Poseidon-European Remote Sensing satellite altimetry dataset. In each of the tropical ocean basins, significant equatorial waves are forced, which are shown to modulate the sea surface temperature (SST) by 0.2-0.3 degC in the absence of strong surface heat fluxes. In the Indian Ocean there is a clear dynamical response which may play a significant role in generating later MJ events. Surface westerly winds, associated with the active phase of the Madden-Julian Oscillation (MJO), force an eastward-propagating oceanic downwelling equatorial Kelvin wave, which, on reaching the eastern boundary at Sumatra, forces reflected downwelling equatorial Rossby waves and coastal Kelvin waves. The coastal Kelvin waves propagate southwards towards northern Australia and northwards into the Bay of Bengal, and will be important for local physical, chemical and biological processes. The equatorial Rossby waves propagate westward across the Indian Ocean, arriving in the western Indian Ocean approximately 80-100 days after the initial Kelvin wave was generated. The arrival of these waves generates positive SST anomalies which leads to convection and may trigger the next-but-one MJ event, or amplify the low-frequency tail of the MJO. This constitutes a coupled feedback mechanism from the ocean dynamics onto the MJO, somewhat similar to the delayed oscillator mechanism for the El Nino Southern Oscillation

Effects of flavopiridol on Cdk2 activity in cultured cell lines

Flavopiradol reduced cyclin-dependent kinase activity by competititve inhibition with ATP by binding to the ATP-binding pocket of these cell cycle regulators ... it was thought that flavopiradol would be an excllent inhibitor of cell proliferation and effective tumor suppressor ... Although apoptosis was not observed after a 24hr incubation period, the antiapoptotic protein Bcl-2 was downregulated. Our findings illustrate an alternate mechanism of cdk2 inhibition in vitro, through p21 WAF1/CIP1 upregulation, showing that drugs that were shown to have specific activities when assayed using purified systems may have multiple in vivo activities and these activities differ depending on the cells used. These different effects may contribute to the variable results seen in clinical trials