—In tallgrass prairie, cicadas emerge annually, are abundant and their emergence can be an important flux of energy and nutrients. However, factors influencing die distribution and abundance of these cicadas are virtually unknown. We examined cicada emergence in plots from a long-term (13 y) experimental manipulation involving common tallgrass prairie management practices. The plots were arrang...

Simian virus 40 (SV40) adsorbs on rabbit spermatozoa but does not penetrate the cells, as indicated by the absence of radioactive material seen on autoradiography of spermatozoa exposed to [(3)H]thymidine-labeled SV40. In contrast, after exposure of spermatozoa to labeled SV40 DNA, radioactive material was found in the postacrosomal area of the spermatozoa. Furthermore, when spermatozoa exposed...

Androgenetic embryonic stem (aES) cells, produced by pronuclear transplantation, offer an important autologous pluripotent stem cell source. However, the isolation of aES cells, particularly individual-specific aES cells, with the use of fertilized embryos has limited the practical applications of this technology in humans. In this study, we applied a new approach, essentially described as soma...

The serine protease tissue-plasminogen activator (t-PA) has previously been shown to be intracellular in mouse secondary oocytes and extracellular in fertilized eggs. Here we demonstrate that extracellular t-PA activity is bound to the surface of the fertilized egg. The level of t-PA activity associated with preimplantation mouse embryos decreases in the 2-cell stage embryo, then increases in 4...

Photosynthetic O(2) evolution and chlorophyll a fluorescence were measured in 1-year-old needles of unfertilized and fertilized trees of Norway spruce (Picea abies (L.) Karst.) during recovery of photosynthesis from winter inhibition in northern Sweden. Measurements were made under laboratory conditions at 20 degrees C. In general, the CO(2)-saturated rate of O(2) evolution was higher in needle...

In this study, the branch, leaves, flowers, roots and mixed all parts of different nine Euphorbia species were analyzed for their trace element contents by using ICP-MS. The samples were digested by concentrated nitric acid and hydrogen peroxide in a microwave by ICP-MS before the analysis. The accuracy and precision of the method was evaluated by CRM 1573a Tomato Leaves. Trace element contents...

Myrciaria dubia (camu-camu) is an Amazonian fruit of economic importance.The most common problems are the damage caused by Conotrachelus dubiae and drop developing fruits. The objective was to clarify factors influencing post-defoliation retention influenced C. in flooded areas. Four treatments were applied: control (T1), bottle trap (T2), adhesive tape (T3), foliar fertilization (T4). research...

We have examined the role of germline-specific chromosomal determinants of development in the mouse. Studies were carried out using aggregation chimaeras between androgenetic----fertilized embryos and compared with similar parthenogenetic----fertilized chimaeras. Several adult chimaeras were found with parthenogenetic cells but none were found with androgenetic cells. Analysis of chimaeras at m...

Taxonomic delimitation of Disepalum (Annonaceae) is contentious, with some researchers favoring a narrow circumscription following segregation of the genus Enicosanthellum. We reconstruct the phylogeny of Disepalum and related taxa based on four chloroplast and two nuclear DNA regions as a framework for clarifying taxonomic delimitation and assessing evolutionary transitions in key morphologica...