Useful reactions in modern pheromone ..
Some have argued that many forms of product quality are purely cosmetic and without a basis in health, nutritional value, or consumer demand (van den Bosch et al. 1975, Pimentel et al. 1991). Federal food-purity standards and grading standards have been especially criticized for that basis. It has been argued that those standards are stricter than necessary and that the stringency of these standards induces farmers to use pesticides more intensively than they otherwise would. Studies of purchases of peaches (Parker and Zilberman 1993), wheat (Ulrich et al. 1987), and other commodities show that consumers are willing to pay more for agricultural products that have fewer blemishes and impurities. Some consumer surveys also indicate unwillingness to purchase produce that has cosmetic defects or insect damage (see, for example, Ott 1990). Studies of pesticide productivity, such as those discussed previously, ignore quality considerations and thus understate benefits of pesticide use. In some cases, aesthetic quality is the primary consideration for pest control, however. Examples include such high-value ornamental crops as flowers, Christmas trees, and woody ornamentals.
Current Organic Synthesis, 1, 11-29
Methyl bromide is a highly effective preplant fumigant with wide use on high-value crops—such as citrus, other fruit, and nut orchard crops; grapes; and strawberries—and in nurseries. After the cancellation of EDB and DBCP, it became the fumigant of choice because of its effectiveness against a wide spectrum of pests, including arthropods, nematodes, fungi, bacteria, and weeds (Noling, 1997). Methyl bromide is an effective postharvest fumigant for stored nuts and other commodities, and its use is required in some cases to circumvent quarantine of produce that might, through shipping, transport pests into uninfested areas. It is also used to fumigate structures; this use has resulted in a few fatal accidents when reentry regulations were not followed after treatment with the chemical. Methyl bromide is a gas at ambient conditions and leaves no organic residue in the treated soil or commodity, because it breaks down to bromide and eventually carbon dioxide. But methyl bromide is stable in the atmosphere, creating a potential for exposure among workers and downwind residents and for diffusion to the stratosphere, where its interaction with high-energy ultraviolet radiation sets off a series of reac-
Greig-Smith, P.W. 1994. Understanding the impact of pesticides on wild birds by monitoring incidents of poisoning. Pp. 301-319 in Wildlife Toxicology and Population Modeling, R.J. Kendall and T.E. Lacher, eds. Boca Raton, Fla.: CRC Press.
Useful Synthesis of Coumestans - [PDF Document]
Bacteriophage lambda infection of Escherichia coli can result in distinct cell fate outcomes. For example, some cells lyse whereas others survive as lysogens. A quantitative biophysical model of lambda infection supports the hypothesis that spontaneous differences in the timing of individual molecular events during lambda infection leads to variation in the selection of cell fates. Building from this analysis, the lambda lysis-lysogeny decision now serves as a paradigm for how intrinsic molecular noise can influence cellular behavior, drive developmental processes, and produce population heterogeneity. Here, we report experimental evidence that warrants reconsidering this framework. By using cell fractioning, plating, and single-cell fluorescent microscopy, we find that physical differences among cells present before infection bias lambda developmental outcomes. Specifically, variation in cell volume at the time of infection can be used to help predict cell fate: a approximately 2-fold increase in cell volume results in a 4- to 5-fold decrease in the probability of lysogeny. Other cell fate decisions now thought to be stochastic might also be determined by pre-existing variation.
Useful Synthesis of Aryl Cinnamates: ..
Natural biological systems are selected by evolution to continue to exist and evolve. Evolution likely gives rise to complicated systems that are difficult to understand and manipulate. Here, we redesign the genome of a natural biological system, bacteriophage T7, in order to specify an engineered surrogate that, if viable, would be easier to study and extend. Our initial design goals were to physically separate and enable unique manipulation of primary genetic elements. Implicit in our design are the hypotheses that overlapping genetic elements are, in aggregate, nonessential for T7 viability and that our models for the functions encoded by elements are sufficient. To test our initial design, we replaced the left 11,515 base pairs (bp) of the 39,937 bp wild-type genome with 12,179 bp of engineered DNA. The resulting chimeric genome encodes a viable bacteriophage that appears to maintain key features of the original while being simpler to model and easier to manipulate. The viability of our initial design suggests that the genomes encoding natural biological systems can be systematically redesigned and built anew in service of scientific understanding or human intention.