The human progesterone receptor (PR) is a ligand-activated nuclear transcription factor that mediates progesterone action in target tissues. Two PR proteins, PR-A (M(r) 81,000-83,000) and PR-B (M(r) 116,000-120,000), have been described and different physiological activities ascribed to each on the basis of in vitro studies, suggesting that their ratio of expression may control progesterone res...

Dimerization of HIV-1 protease (PR) subunits is an essential process for PR's acquisition of proteolytic activity, which plays a critical role in the maturation of HIV-1. Recombinant wild-type PR (PR(WT)) proved to dimerize, as examined with electrospray ionization mass spectrometry; however, two active site interface PR mutants (PR(T26A) and PR(R87K)) remained monomeric. On the other hand, two...

For rat pituitary cells, progesterone receptor (PR) protein localizes to gonadotropes and PR messenger RNA is induced by E2 and rapidly but transiently down-regulated by progesterone. Here we quantitatively establish the down-regulatory effect of progesterone on PR protein and evaluate possible mechanisms. Nuclear PR-immunoreactivity (PR-IR) in gonadotropes, identified by dual immunofluorescenc...

Knoevenagel condensation between barbituric acid and aldehyde was investigated in the presence of sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) and resulted in the formation of arylidene and bis-arylidene barbiturates. Excellent yields and short reaction times are related to the high efficiency of SBA-Pr-SO3H that the reactions take place easily in its nano-pores. SBA-Pr-SO3H as ...

In standard treatments of probability, Pr(A|B) is defined as the ratio of Pr(A intersectionB) to Pr(B), provided that Pr(B)>0. This account of conditional probability suggests a psychological question, namely, whether estimates of Pr(A|B) arise in the mind via implicit calculation of Pr(A intersectionB)/Pr(B). We tested this hypothesis (Experiment 1) by presenting brief visual scenes composed o...

Fix > 0, and let p1 = 2, p2 = 3, . . . be the sequence of all primes. We prove that if (q, a) = 1, then there are infinitely many pairs pr, pr+1 such that pr ≡ pr+1 ≡ a mod q and pr+1 − pr < log pr. The proof combines the ideas of Shiu and of Goldston–Pintz–Yıldırım.

One of the basic principles behind conditioning is that “conditioning on a high-probability event keeps things reasonably unchanged; however, if we condition on a low-probability event, then all bets could be off”. More precisely, suppose we wish to estimate Pr[A | B]. Note, in general, that this could be less than, equal to, or greater than Pr[A]. We now prove that if Pr[B] is “high”, then Pr[...