We show the existence of a unique analytic single parameter limiting survival function arising from the repeated composition of a coherent structure as the number of components tends to infinity. Examples include the repeated composition process of the bridge structure. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.

The vector epsilon algorithm (VEA) is a non-linear sequence-to-sequence transformation which has been in use for over 35 years to determine the limits (antilimits) of convergent (divergent) vector sequences. Recently, it has been used in a variety of engineering applications to accelerate iterative solution processes, including iterative finite element techniques. The VEA has been shown to give the limiting value of many sequences. However, an expression describing the kernel of the VEA, the set of all sequences {v(n)} which the VEA extrapolates successfully to the sequence's limit (antilimit) vector v, remains elusive. Here, this question is addressed with a simple proof giving the kernel of the first-order VEA with some comments about the kernel for higher orders. We prove that the first-order VEA assumes that each term of the related sequence {v(n) - v} is rotated by a fixed angle and scaled in length by a constant factor with respect to the preceding term. Copyright (C) 2000 John Wiley & Sons, Ltd.

<p>Prior to the imposition of effective source‐control measures in 1970, large quantities of DDT were discharged to the Los Angeles County municipal sewer system and, subsequently, to the Pacific Ocean. A fraction of this material accumulated among sediments of the Palos Verdes shelf. While the bulk of the DDT lies 10–40 cm below the sediment surface, its fate may be affected by future wastewater‐treatment decisions at the Joint Water Pollution Control Plant (JWPCP), Los Angeles County's 385‐mgd treatment plant. To assess the impact of impending JWPCP secondary treatment requirements on shelf sediment quality (processes that potentially affect the distribution of chemical tracers among those sediments, including background sedimentation rate), contributions from effluent‐related solids, sediment mixing, and diffusive transport were incorporated in mathematical models. Model projections of surface‐sediment quality at the most heavily contaminated sites are sensitive to projected effluent solids concentrations, and thus treatmentlevel decisions at JWPCP. Full secondary treatment projections of surface‐sediment DDT concentration are 75% higher than those corresponding to continuation of present treatment practice.</p>

The cyclic tetrapeptide [d-MeAla1]-tentoxin (2) has been found to exist in multiple conformations in solution. Two of these (2U and 2L) have been isolated. Circular dichroism spectroscopy was used to show that the conformations of 2U and 2L differed from each other in water. The potencies of 2U and 2L as inhibitors of coupled electron transport in isolated chloroplasts and as inhibitors of chloroplast coupling factor one ATPase (CF1-ATPase) were determined. Conformer 2L is the more potent inhibitor of coupled electron transport. In the CF1-ATPase assay, conformer 2L is a more potent inhibitor than 2U but the potency of each is much less than that of tentoxin. The reported results provide the first demonstration that separate conformers of a single molecule can have differing biological activities.

A method of analyzing the results of continuous ultrafiltration experiments to obtain protein-ligand binding parameters is presented. This method employs a nonlinear least-squares regression algorithm coupled with a model of protein-ligand binding which allows the computation of free ligand concentrations, and a second-order Runge-Kutta method to integrate free concentrations with respect to collected ultrafiltrate. The approach is general and effectively removes the constraints on maximum fraction size imposed by other methods.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTProtection of the Hydroxyl Group with Vinyl ThioethersLouis A. Cohen and John A. SteeleCite this: J. Org. Chem. 1966, 31, 7, 2333–2336Publication Date (Print):July 1, 1966Publication History Published online1 May 2002Published inissue 1 July 1966https://pubs.acs.org/doi/10.1021/jo01345a060https://doi.org/10.1021/jo01345a060research-articleACS PublicationsRequest reuse permissionsArticle Views278Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

The sterol of houseflies (Musca domestica L.) reared by the CSMA procedure, and previously designated as ‘Muscasterol’ in the literature, is a mixture of at least two sterols. The major sterol (74 per cent) was shown to be campesterol. The other component (21 per cent) was identified as β-sitosterol. Experimental results show that the housefly sterols originate from the CSMA medium and that there is a selective uptake and/or retention of campesterol by the housefly. When the housefly is reared on a diet containing more than one Δ5-3β-hydroxy sterol, there is a selective absorption or retention of that sterol in which the side-chain more nearly approximates that of cholesterol.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Anthrasteroid Rearrangement. VIII.1 The Rearrangement of Dehydroergosterol and Δ5,7,9(11)-Cholestatriene-3β-ol to Δ5,7,9,22-Anthraergostatetraen-x-ols and Δ5,7,9-Anthracholestatrien-x-olsKyosuke. Tsuda, Ryoichi. Hayatsu, John A. Steele, Osamu. Tanaka, and Erich. MosettigCite this: J. Am. Chem. Soc. 1963, 85, 8, 1126–1131Publication Date (Print):April 1, 1963Publication History Published online1 May 2002Published inissue 1 April 1963https://doi.org/10.1021/ja00891a020RIGHTS & PERMISSIONSArticle Views76Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (851 KB) Get e-Alerts Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Solvolysis of Stigmasteryl TosylateJohn A. Steele and Erich MosettigCite this: J. Org. Chem. 1963, 28, 2, 571–572Publication Date (Print):February 1, 1963Publication History Published online1 May 2002Published inissue 1 February 1963https://pubs.acs.org/doi/10.1021/jo01037a505https://doi.org/10.1021/jo01037a505research-articleACS PublicationsRequest reuse permissionsArticle Views526Altmetric-Citations85LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Quantitative analyses have been made of the dietary cholesterol requirement for the growth of the larvae of Musca domestica. The larvae will not grow on diets to which no cholesterol is added, a few pupae and adults are obtained when the concentration of cholesterol is 0·05 μmol/g of diet, but the concentration has to be raised to 0·36 μmol/g of diet before the maximum numbers of pupae and adults are obtained. Further addition of cholesterol above 0·36 μmol/g diet did not have any significant effect on the weight and growth of the larvae. However, the ratios of the cholesterol to phospholipid fractions recovered from the larvae increased rapidly when the concentration of cholesterol in the diet was raised from 0·05 to 0·56 μmol/g of diet. Above this concentration only a slight increase in the ratios was observed. Larvae reared on diets containing 0·05 μmol cholesterol/g of diet contain only 25 per cent of the cholesterol content of the larvae reared on the diets containing more than 0·28 μmol of cholesterol/g of diet, the cholesterol content being expressed relative to the weight of the larvae,The absence of cholesterol synthesis has been demonstrated in the larvae by feeding [4-14C] cholesterol. The specific activity of the cholesterol recovered from the larvae is the same as that of cholesterol added to the diet. Irrespective of the cholesterol concentration of the larval diet, approximately 97 per cent of the radioactivity recovered from the larvae behaved as free cholesterol, less than 1 per cent as cholesterol esters and the rest as unidentified ‘polar sterols’. The results are compared with those from similar studies on other insects.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Anthrasteroid Rearrangement. V. The Preparation of an Analog of Progesterone1William R. Nes, John A. Steele, and Erich MosettigCite this: J. Am. Chem. Soc. 1958, 80, 19, 5230–5232Publication Date (Print):October 1, 1958Publication History Published online1 May 2002Published inissue 1 October 1958https://doi.org/10.1021/ja01552a052RIGHTS & PERMISSIONSArticle Views85Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (439 KB) Get e-Alerts Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Anthrasteroid Rearrangement. VI. The Preparation of an Analog of the Androgens and Estrogens1William R. Nes, John A. Steele, and Erich MosettigCite this: J. Am. Chem. Soc. 1958, 80, 19, 5233–5235Publication Date (Print):October 1, 1958Publication History Published online1 May 2002Published inissue 1 October 1958https://pubs.acs.org/doi/10.1021/ja01552a053https://doi.org/10.1021/ja01552a053research-articleACS PublicationsRequest reuse permissionsArticle Views70Altmetric-Citations4LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfluence of a 9(11)-Double Bond on the Course and Mechanism of Alkyl-Oxygen Cleavage Reactions of Unsaturated Steroids*WILLIAM R. NES and JOHN A. STEELECite this: J. Org. Chem. 1957, 22, 11, 1457–1465Publication Date (Print):November 1, 1957Publication History Published online1 May 2002Published inissue 1 November 1957https://pubs.acs.org/doi/10.1021/jo01362a038https://doi.org/10.1021/jo01362a038research-articleACS PublicationsRequest reuse permissionsArticle Views178Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts