After a month of celebrating the largest boost in federal spending on scientific research that most of them have ever seen, university presidents are increasingly tuned to the possibility of a downside. The new money--primarily from a $21.5-billion jump in research-and-development spending in the economic-stimulus law--is certainly welcome, several university presidents and higher-education officials said during a lobbying trip to Capitol Hill. Yet, the leaders said, many institutions struggled over the past decade to retain promising young researchers and their investigative projects through upward and downward spikes in the budget of the National Institutes of Health. And they're now hoping to avoid repeating that pattern with the stimulus money. The higher-education leaders also raised with lawmakers some more-immediate concerns about the stimulus money. Congress approved the $787-billion economic-stimulus package with the understanding that it would help create jobs across the country. But some critics have questioned whether certain elements of the stimulus measure, including expenditures on scientific research, would make an immediate and significant dent in the nation's unemployment rate. The need to prove the job-creation value of the stimulus law has left colleges facing an unprecedented level of paperwork and regulatory interpretations in tallying how many workers benefit from a particular project. University leaders said they were confident their use of a range of federal stimulus money will lead to job growth, especially in their local communities. Although university leaders said they believe they can make the argument on job creation, some of them have admitted concern about how fast they can do it. Research takes time, and results take time.