A selective scheme is presented for isolating sequences capable of replicating autonomously in the yeast Saccharomyces cerevisiae. YIp5, a vector Table 1. YNN27 is a ura3-52 strain that is transformed by YRp12 (see Fig. 2) at a particularly high frequency (2000-10,000 colonies per gg of DNA). It was obtained by crossing YNN6 and YNN34 and assessing the transformation ability of strains grown from individual spores. Growth and storage conditions used for all strains have been described (27).DNA. Bacterial plasmid DNA was purified by repeated isopycnic centrifugation in CsCl (27). Chromosomal yeast DNA was prepared by the method of Cameron (28). N. crassa DNA was purified from conidia (unpublished method). E. coil, D. melanogaster, D. discoideum, C. elegans, and Z. mays DNAs were generous gifts of Lee Rowan, Louise Prestidge, Alan Jacobsen, David Hirsh, and Irwin Rubenstein, respectively. pSY317, a kanamycin-resistant plasmid carrying the E. coli origin of replication, was provided by Seiichi Yasuda.Enzymes and Reagents. EcoRI endonuclease was purified by the published procedure (29). T4 DNA ligase and DNA polymerase I were generously provided by Stewart Scherer. All other enzymes and reagents were purchased from commercial suppliers and were used as described (27).Construction of Hybrid DNA Molecules. Random DNA fragments were inserted into YIp5 to produce pools of hybrid molecules. After digestion with the appropriate restriction endonuclease(s) (EcoRI, HindIII, BamHI, or codigestion with EcoRI and HindIII), the YIp5 and chromosomal DNAs (each at 15-20 ,ug of DNA per ml) were mixed and ligated with 0.1 ,g of T4 DNA ligase in 100 mM NaCl/50 mM Tris-HCl, pH 7.4/10 mM MgSO4/1 mM ATP/10 mM dithiothreitol at 40C for hr. This ligation mixture was directly used to transform yeast cells.Hybrids were constructed between YIp5 and the E. coil origin of replication, oriC, by mixing and ligating EcoRI-digested pSY317 and YIp5 DNAs (as described above). The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U. S. C. §1734 solely to indicate this fact.

This paper addresses the problem of crude-oil short-term scheduling, which is the first part of the overall refining operations. The problem involves the optimal operation of crude-oil unloading from vessels, its transfer to storage tanks, and the charging schedule for each crude-oil mixture to the distillation units. A novel model is developed based on a continuous-time representation and results in a mixed-integer linear programming (MILP) problem. The state-task network representation is used throughout this paper. The proposed formulation is applied to several case studies and leads to fewer binary and continuous variables and fewer constraints compared with existing discrete-time models. Thus, an efficient solution can be achieved using available MILP solvers.

Nonlinear planning and scheduling models for crude-oil atmospheric and vacuum distillation units are essential to manage increased complexities and narrow margins present in the petroleum industry. Traditionally, conventional swing-cut modeling is based on fixed yields with fixed properties for the hypothetical cuts that swing between adjacent light and heavy distillates, which can subsequently lead to inaccuracies in the predictions of both its quantity and quality. A new extension is proposed to better predict quantities and qualities for the distilled products by taking into consideration that we require corresponding light and heavy swing-cuts with appropriately varying qualities. By computing interpolated qualities relative to its light and 2 heavy swing-cut quantities, we can show an improvement in the accuracy of the blended or pooled quality predictions. Additional nonlinear variables and constraints are necessary in the model, but it is shown that these are relatively easy to deal with in the nonlinear optimization.

Two genomic libraries were established to provide markers to develop an integrated map combining molecular markers and genes for qualitative and quantitative morpho-agronomic traits in common bean. Contrasting characteristics were observed for the two libraries. While 89% of the PstI clones were classified as single-copy sequences, only 21% of the EcoRIBamHI clones belonged in that category. Clones of these two libraries were hybridized against genomic DNA of nine genotypes chosen according to their divergent evolutionary origin and contrasting agronomic traits. Eight restriction enzymes were used in this study. PstI clones revealed 80-90% polymorphism between the Andean and Middle American gene pools and 50-60% polymorphism within these gene pools. However, under the same conditions only 30% of the EcoRI-BamHI clones showed polymorphism between the Middle American and Andean gene pools. Hybridization with PstI clones to EcoRI-, EcoRV-, or HindIII-digested genomic DNA resulted in a cumulative frequency of polymorphism of approximately 80%. Hybridizations to BamHI-, HaeIII-, HinfI-, PstI-, and XbaI-digested genomic DNA detected no additional polymorphisms not revealed by the former three enzymes. In the PstI library, a positive correlation was observed between the average size of hybridizing restriction fragments and the frequency of polymorphism detected by each restriction enzyme. This relationship is consistent with the higher proportion of insertion/deletion events compared with the frequency of nucleotide substitutions observed in that library.

Animal-scavenging alterations on human remains can be mistaken as human criminal activity. A 32-day study, documenting animal scavenging on a human cadaver, was conducted at the Southeast Texas Applied Forensic Science facility, Sam Houston State University, Huntsville, Texas. A Stealth Cam Rogue IR was positioned near the cadaver to capture scavenging activity. An atypical scavenger, the bobcat, Lynx rufus, was recorded feeding on the cadaver. Scavenging by bobcats on human remains is not a predominant behavior and has minimal documentation. Scavenging behaviors and destruction of body tissues were analyzed. Results show that the bobcat did not feed on areas of the body that it does for other large animal carcasses. Results also show the bobcat feeds similarly during peak and nonpeak hours. Understanding the destruction of human tissue and covering of the body with leaf debris may aid forensic anthropologists and pathologists in differentiating between nefarious human activity and animal scavenging.