[This corrects the article on p. 585 in vol. 42.].

The problem of the localization of intranucleolar DNA in root meristematic cells of Allium cepa has been investigated under both light and electron microscopy following formaldehyde fixation coupled with deoxyribonuclease extraction. The observations reveal that most, if not all, of the intranucleolar DNA is located inside small lacunar spaces confined to the fibrillar regions of the nucleolar ...

. Figure 1. Cambrian lobopodian diversity. (A) Aysheaia pedunculata, middle Cambrian Burgess Shale (NMNH-83942). (B) Claws of Aysheaia pedunculata (NMNH-365608). (C) Hallucigenia sparsa, middle Cambrian Burgess Shale (NMNH198658; courtesy of M. Smith, University of Cambridge. Nature 523, 75–78). (D) Microdictyon sinicum, early Cambrian Chengjiang (ELRC-30060; courtesy of G. Edgecombe, Natural H...

We evaluated the antiproliferative effect of infusions from Pluchea sagittalis using the Allium cepa test. Infusions in three concentrations (2.5, 5, and 25 g dm-3) of leaves cultivated in three environments (in vitro, acclimatized growth chamber, and field) were used. Six onion bulbs were used for each of the eight treatments, and the mitotic index was obtained from 6000 cells per treatment. I...

The Purpose of the study was the isolation and identification of Urinary tract infection (UTI) bacteria and the evaluation of their susceptibility against antibiotics. In addition, susceptibility and chemotactic behavior of isolated strains were evaluated against medicinal herbal plant extracts. To perform the study, 200 samples were collected from the patients suffering from UTI. Then, the bac...

The Wigner-Araki-Yanase theorem shows that conservation laws limit the accuracy of measurement. Here, we generalize the argument to show that conservation laws limit the accuracy of quantum logic operations. A rigorous lower bound is obtained of the error probability of any physical realization of the controlled-NOT gate under the constraint that the computational basis is represented by a comp...

Effect of abscisic acid (ABA) and polyamines (PAs) [putrescine (Put), spermidine (Spd) and spermine (Spm)] on mitosis in root tips of A. cepa was studied. Treatment with ABA (0.1 to 100 microM) for 24 hr suppressed the mitosis, measured as mitotic index (MI), in a concentration-dependent manner with approx. 50% suppression at 10 microM of ABA. Treatment with different PAs (1 to 100 microM) had ...