Polyamines in spermiogenesis: Not now, darling

Polyamines in spermiogenesis: not now, darling.

I processes invariably employ interesting biochemistry,” declares Marc Kirschner (1). From this statement, one may readily conclude that antizyme (AZ) deserves our attention. AZ is the central element in a feedback loop that controls cellular polyamines. AZ is interesting for a number of reasons. First, AZ production requires the exercise of a remarkable mechanism, translational frameshifting. ...

Not tonight, darling, I might get a headache.

Do not wait, act now.

See related article, pages 3213–3217. Utilizing a population-based study1 Dr Majersik and her coworkers provide excellent data on stroke patient arrival times in a community without academic centers. Because most patients present after 3 hours from stroke onset—the ratio in their study is 62% to 69% of patients— the idea of Majersik and her coworkers is to extend the time window beyond 3 hours ...

Annuitization : If Not Now , When ?

In previous writing – and related papers by Chen and Milevsky (JFP, 2003) or Ameriks, Veres and Warshawsky (JFP, 2001) – the point has been made that payout annuities, either variable or fixed, have a rightful place in the optimal life-cycle portfolio. I have argued that depending on a lifecycle investor’s bequest motive versus their desire for consumption, they should have a substantial portio...

Spermiogenesis in Lumbricus herculeus

Small pieces of the sperm sacs of Lumbricus herculeus were fixed for 4 hours in chrome-osmium, embedded in methacrylate, sectioned with a Porter-Blum microtome, and studied with a R.C.A. EMU-2C electron microscope. Each spermatid of a group developing synchronously is attached by a cytoplasmic strand to a common nutrient protoplasmic mass. This mass contains mitochondria and yolk bodies but is ...