Recurring Theme

In 1973, a report by the GAO found that the regulator s own standard for the frequency with which to inspect offshore assets in the Gulf of Mexico was rarely being met, 9 despite the increase in the number of inspection staff. It highlighted the need 

National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling (2010) The History of Offshore Oil and Gas in the United States (Long Version). Washington, DC. See also Staff Working Paper N0.22, 2010, p. 13 (hereinafter. Commission, History of Offshore). 

Commission, History of Offshore, p. 13. In 1969, the Gulf region s lease management office had only 12 people overseeing more than 1,500 platforms.  

These include blowouts (22 deaths on the C.P. Baker catamaran drilling vessel in 1964), helicopter crashes (eleven in one crash in 1966) , a near-miss crash of a Louisiana Air National Guard jet on an ODECO rig, Santa Barbara oil spill following a blowout at Union Oil s Platform A-21 in 1969 and another blowout in 1970 at Chevron s Platform C in Main Pass block 41. For more discussion on these incidents, see MMS, History of Offshore Vol. I, pp. 145-146. 

GAO (1973) Improved Inspection and Regulation Could Reduce The Possibility of Oil Spills On the Outer Continental Shelf. Report to the Conservation and Natural Resources Subcommittee on Government Operations, House of Representatives by the Comptroller General of the United States, B-146333, 29 June 1973 (hereinafter, GAO 1973 Report). Note that at the time the acronym GAO stood for General Accounting Office and not Government Accountability Office, despite being the same entity. 

---

The enzyme catalyzed reactions that lead to geraniol and farnesol (as their pyrophosphate esters) are mechanistically related to the acid catalyzed dimerization of alkenes discussed m Section 6 21 The reaction of an allylic pyrophosphate or a carbo cation with a source of rr electrons is a recurring theme m terpene biosynthesis and is invoked to explain the origin of more complicated structural types Consider for exam pie the formation of cyclic monoterpenes Neryl pyrophosphate formed by an enzyme catalyzed isomerization of the E double bond m geranyl pyrophosphate has the proper geometry to form a six membered ring via intramolecular attack of the double bond on the allylic pyrophosphate unit... 

In the following sections, I have tried to pick out some of the more familiar techniques and concepts that will form recurring themes throughout the text. 

Ornston LN, W-K Yeh (1982) Recurring themes and repeated sequences in metabolic evolution. In Biodegradation and Detoxification of Environmental Pollutants (Ed AM Chakrabarty), pp. 105-126. CRC Press Inc, Boca Raton. 

Catalytic transformations can be divided on the basis of the catalyst-type - homogeneous, heterogeneous or enzymatic - or the type of conversion. We have opted for a compromise a division based partly on type of conversion (reduction, oxidation and C-C bond formation, and partly on catalyst type (solid acids and bases, and biocatalysts). Finally, enantioselective catalysis is a recurring theme in fine chemicals manufacture, e.g. in the production of pharmaceutical intermediates, and a separate section is devoted to this topic. 

The recurring theme in work on corticoids discussed thus far with the exception of the 17-desoxy compounds consisted in the introduction of additional functions to the basic cortisone molecule. Some further success in producing biologically active molecules has been achieved by substituting unnatural functions for those present in the protoype molecule. Thus the hydroxyl groups at both C-ll and C-21 can be replaced by halogen with retention of activity. 

DERIVATIVES OF DIBENZOLACTAMS A recurring theme in the present chapter has been the association of CNS activity with dibenzoheterocycles that bear a basic chain pendant from the central ring. As we have seen, considerable latitude exists as to the constitution of the central ring. The earlier volume in this series described the preparation of the antidepressant dibenzepin (90), in which the basic function is attached to a lactam nitrogen. 

Cross-reactivity with JAK kinases is a recurring theme with pyrimidine-carboxamides [81,82], but compound 20 exemplifies a Syk-selective series [81]. Pyrimidine amide 20 has an IC50 of 6nM against Syk, and broad screening (at 300 nM concentration) demonstrated significant selectivity for Syk over 270 kinases. In Ramos cells, 20 inhibited BCR-induced phosphorylation of BLNK, a direct substrate of Syk, with an EC50 of 500-750 nM and Ca2+ flux with an EC50 = 117 nM. Compound 20 potently... 

A detailed understanding of the course of a reaction between a polymer and an additive will permit one to use that information to design new flame retardants. The reaction between poly(methyl methacrylate), PMMA, and red phosphorus is described and that information used to determine that CIRh(PPh3)3 should be used as a flame retardant. The results of this investigation are then used to choose the next additive. A recurring theme is the efficacy of cross-linking as a means to impart an increased thermal stability. 

IN addition to covering traditional areas such as mechanism of action, structure-function relationships, and drug disposition and toxicity, this part of the volume reviews drug-specific data that are specifically pertinent to children and adolescents. Age and developmental phase as critical variables relevant to dosing schemes and side effect liabilities are two recurring themes. Clinical mechanics for using these... 

The reaction of 2- and 4-pyridones, fused as part of a variety of 6,6-heterocyclic systems, is a recurring theme in many publications for example, conversion of diethyl 4-oxo-l,5,7,8-tetrahydro-4//-[l,6]naphthyridine 3,6-dicarboxy-late into the 4-chloro derivative <2004BML3441>, and others will appear through the chapter. 

At the core of Peters perspective is the ability to be able to handle the paradox of managing projects. On the one hand, one needs voluntary co-operation, while at the same time one needs to be able to exercise the toughness and single-mindedness necessary to achieve results. This is a recurring theme in his writings. Box 1.4 summarizes, from the plethora of prescriptions that pervade his books, what 1 regard to be his centr principles. 

Two other features deserve mention. First, there is evidence, especially in the de novo purine pathway, that the enzymes are present as large, multienzyme complexes in the cell, a recurring theme in our discussion of metabolism. Second, the cellular pools of nucleotides (other than ATP) are quite small, perhaps 1% or less of the amounts required to synthesize the cell s DNA. Therefore, cells must continue to synthesize nucleotides during nucleic acid synthesis, and in some cases nucleotide synthesis may limit the rates of DNA replication and transcription. Because of the importance of these processes in dividing cells, agents that inhibit nucleotide synthesis have become particularly important to modern medicine. 

Intramolecular Iminium Ion-Sulfide Charge-Transfer Association A Recurring Theme in the Study of Thiaspirane Alkaloids R. T. LaLonde, Acc. Chem. Res., 1980,13, 39-44. Recent Advances in the Chemistry of Berbine Alkaloids G. D. Pandey and K. P. Tiwari, Heterocycles, 1980,14, 59-82. 

---