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The paper presents the results of a life cycle inventory (LCI) for various structural engineering design strategies. The strategies focus on alternative design approaches the structural engineer ca...

The economic, policy-related and technical barriers to the introduction of new sustainable engineering practices in the USA are described. Ways of overcoming these barriers are discussed with reference to using high volume fly ash concrete, recycled concrete aggregates, and supplementary cementitious materials. The development of specifications that include sustainable practices is discussed and an example of a green concrete specification is presented. Experiences gained by the author in introducing green specifications are outlined.

Elevated nocturnal melatonin is found in women with idiopathic hypogonadotropic hypogonadism (IHH), but it is not known whether this is implicated in the etiology of their GnRH deficiency. It is unlikely that nocturnal melatonin can be implicated in the etiology of the GnRH deficiency of Kallmann's syndrome (KS), because this condition is caused by defective neuronal migration in embryonic life. We therefore measured nocturnal melatonin in women with IHH and KS to determine whether it was elevated in one or both conditions and thereby to determine whether it was implicated as cause or consequence of GnRH deficiency. Four women with IHH, 3 women with KS, and 7 individually matched (age and body size) controls were recruited. Frequent day- and nighttime samples were taken for LH pulsatility studies. All patients showed absent or diminished LH pulsatility, compared with their respective controls. Samples were also taken over 24 h for melatonin and 6-sulphatoxymelatonin (the principle metabolite of melatonin and an independent marker of its secretion). Melatonin and 6-sulphatoxymelatonin levels were elevated in 6 of 7 patients (compared with their matched controls) and were significantly elevated in the KS group (compared with their controls). The finding of elevated nocturnal melatonin (and its metabolite) in GnRH-deficient women with KS (as well as IHH) suggests that nocturnal melatonin is elevated as a consequence of GnRH deficiency, irrespective of its etiology.

IABSE and its members can play an active role in alleviating world poverty. We have the means, it just takes the will.

Fetal antigen 2 (FA-2) has been identified in amniotic fluid and shown to be of fetal origin. In this study we have extended previous observations on FA-2 heterogeneity with respect to both size and charge using gel filtration, ion-exchange chromatography, non-dissociating polyacrylamide gel electrophoresis and sodium dodecyl sulphate polyacrylamide gel electrophoresis. From the diversity of forms we have been able to define two principal FA-2 types, type A and type B. Type A has a high molecular mass (140 kDa), has subunits of 33 kDa and 29 kDa, and elutes at approximately 0.27 mol/l sodium chloride from diethylaminoethyl (DEAE)-Sephacel. Type B has the same mass and subunits as type A, but elutes at approximately 0.24 mol/l sodium chloride from DEAE-Sephacel. Other low molecular mass forms of FA-2 have also been identified. All FA-2 forms described were shown to be common to all amniotic fluid samples studied and were not attributable to artefacts of collection or storage. It was also demonstrated that the recently described FA-2 RIA is specific for FA-2 types A and B and the conversion of arbitrary units FA-2 into micrograms applies to type A. The typing is discussed with respect to (i) the aminopropeptide of the alpha 1 chain of human procollagen type I, (ii) the 24 kDa phosphoprotein in developing bone and (iii) fetal calf ligament protein 1 (FCL-1), suggesting that they are the same protein.

We report an HPLC assay for melatonin that incorporates automated injection, methanol/water mobile phase, and fluorescence detection. Plasma samples were extracted by solid and liquid phases. Recovery was > 70% for 1-10 mL of plasma extracted, approximately 40 pg-250 ng of melatonin. Samples were dried and reconstituted in 100 mL/L methanol. Injections were 25 microL or 150 microL, depending on sample concentration, and the melatonin peak was eluted in 380 mL/L methanol. The detection limit of the assay was 6 pg on the column, allowing a practical sensitivity in plasma of 11 pmol/L for 8-mL samples and 34 pmol/L for 2-mL samples. More than 100 plasma samples from volunteers and patients were assayed and the results compared with an established RIA. The mean daytime concentration of melatonin was 20.7 pmol/L (SEM = 1.2) and 18.5 pmol/L (SEM = 1.6) for HPLC and RIA, respectively, and the mean nighttime concentration was 82.4 pmol/L (SEM = 6.5) and 82.2 (SEM = 7.3), respectively.

The seasonal change in the duration of the night time release of melatonin is responsible for activating the hypothalamic gonadtrophin-releasing hormone (GnRH) pulse generator in seasonal breeding animals. Paul Mullen and I considered that it might also be responsible for the activation of the child's GnRH pulse generator at the onset of human puberty. The real conundrum, though, is why this should happen when it does. Homeostasis, which explains how the body is able to maintain itself, cannot explain why things change. Our reasoning was that in any homeostatic state, there might exist two systems in disequilibrium, which eventually collide to create the ‘catastrophe’ of change. Our research showed that a constant daily output of melatonin throughout life was in disequilibrium with increasing body mass throughout childhood. These two systems permit the progressive decrease in the circulating concentration of melatonin in the growing child until it drops below a critical threshold, which then creates the ‘catastrophe’ of puberty. Catastrophe is destined to overthrow the established order, whereas homeostasis protects it. Catastrophe is always a transient moment that is rapidly supplanted by the re-imposition of homeostasis. Copyright © 2010 John Wiley & Sons, Ltd.

This paper will investigate some traditional ethical systems and their relevance to our every day practice of structural engineering. Ethics will be equated to responsibility, as the unprecedented demands of technology require.

[EN] The fireproof character of Guastavino vaults, one of the major characteristics of their structure, has been demonstrated on several occasions over the past hundred and twenty years. The firm of Robert Silman Associates has verified the versatility and solidity of these vaults in several restoration works. This article deals with the fire that broke out on 29th June 1997 in the Oyster Bar at Grand Central Station, which did not impair the structural integrity of the Guastavino vaults so that only cosmetic repairs to the lowest layer of tiles were required., [ES] El carácter ignífugo de las bóvedas de Guastavino, una de las principales características que avalaba la validez de sus estructuras, se ha demostrado en varias ocasiones durante el transcurso de los últimos ciento veinte años. El estudio Robert Silman Associates ha podido comprobar la versatilidad y la solidez de estas bóvedas en diversas intervenciones de restauración de las mismas. En este artículo se presenta el caso del incendio del 29 de junio de 1997 en el Oyster Bar de la Estación Grand Central, que no llegó a afectar a la integridad de las bóvedas de Guastavino, de manera que sólo fueron necesarias algunas reparaciones de tipo cosmético en la capa inferior de rasillas vidriadas.

Fetal antigen 2 (FA-2) is a human protein, first identified in amniotic fluid, and shown to be identical to the aminopropeptide of the alpha 1 chain of collagen type I. It exists in several different size and charge forms. In the present study, FA-2 was measured in amniotic fluid using two different assays: a rocket line immunoelectrophoretic assay which measured total FA-2, and a radioimmunoassay which was specific for the high molecular mass forms of FA-2. Both assays gave similar results. FA-2 concentrations were measured in amniotic fluid samples collected from normal pregnancies at 10-23 weeks gestation; they were shown to rise steeply from 10-14 weeks, peak at 17 weeks and then fall slightly by 23 weeks. Comparison between amniotic fluid from normal pregnancies and pregnancies affected by trisomy, showed significantly higher FA-2 concentrations in trisomy 21 and significantly lower concentrations in trisomy 18.

We describe a nonextraction procedure, and two extraction procedures, for RIA of melatonin in human plasma. All procedures showed a diurnal rhythm of melatonin in human subjects, with interindividual differences greater than interprocedure differences. However, further investigations demonstrated considerable variability of recovery in the nonextraction procedure, suggesting a variability of binding proteins between samples. Combining recovery and dialysis experiments in the extraction procedures, we demonstrated that chloroform was unable to extract albumin-bound melatonin from a human serum albumin solution but, paradoxically, was able to extract bound and free melatonin from a plasma sample. The methanol extraction procedure extracted free and bound melatonin from all sources. These results indicate that albumin binding can substantially affect the RIA procedures. We conclude that assays should be validated against free and bound melatonin and that the two forms should be independently investigated when assessing bioactivity.

Serum concentrations of fetal antigen 2 (FA-2), the amino-propeptide of the alpha1 chain of collagen type I, were measured in peripheral blood from women with normal (n = 234) and trisomy 21 affected (n = 14) pregnancies between 9 and 11 weeks gestation. Serum FA-2 concentrations were seen to be stable throughout this period, and though raised FA-2 concentrations were seen at the 10th week of gestation, a statistically significant difference between normal and trisomy 21 affected pregnancies was not found overall. Therefore it seems unlikely that FA-2 has a role in first trimester screening for trisomy 21, despite the fact that significantly higher FA-2 concentrations in trisomy 21 and significantly lower concentrations in trisomy 18 had been previously demonstrated in amniotic fluid in the second trimester.

To the Editor: It has been claimed that melatonin has many actions, mostly on the basis of uncontrolled studies of widely varying oral doses. It is commonly assumed that the administered dosage of melatonin bears a direct relation to its circulating concentration. We estimated the bioavailability of oral melatonin by determining the pharmacokinetics of intravenous bolus and oral doses of melatonin (Sigma Chemical, St. Louis) in four normal men (21 to 32 years old), who were given 20 μg intravenously on one occasion and 500 μg orally on a second occasion, with an interval of at least one month between . . .

BACKGROUND AND OBJECTIVE Idiopathic hypogonadotrophic hypogonadism (IHH) is a condition of gonadotrophin releasing hormone (GnRH) deficiency. IHH associated with anosmia is Kallmann’s syndrome. A variant has been described by Bauman where a patient with Kallmann's syndrome apparently regained normal hypothalamo-pituitary function 2 years after the initial diagnosis. GnRH secretory activity can be assesed by measuring LH pulsatility. Our objective was to define the pattern of LH pulsatility in men with IHH and Kallmann’s syndrome compared with those of normal controls, and to determine whether there is evidence for a Bauman variant of Kallmann's syndrome. DESIGN Patients with IHH and Kallmann’s syndrome were recruited from the endocrine clinic. Long-term hormone replacement therapy was discontinued. LH pulsatility was determined. PATIENTS Three men with IHH, 3 men with classical Kallmann’s syndrome and 5 normal male volunteers. MEASUREMENTS Baseline serum FSH, LH and testosterone. Intensive blood sampling every 10 minutes for serum LH from 1000 to 1600 h during the day and 2200 to 0400 h during the night to measure LH pulsatility. RESULTS The volunteer group showed normal LH pulsatility. In the patient group, LH secretion was apulsatile in one, showed significantly diminished amplitude in four, and there was normal pulsatility in one patient which remained normal 5 months later. CONCLUSION Three patients with idiopathic hypo-gonadotrophic hypogonadism and 2 with Kallmann's syndrome had variable degrees of GnRH deficiency. One patient with Kallmann's syndrome had apparently normal GnRH activity, which remained normal 5 months later. This patient appears to have the Bauman variant of Kallmann's syndrome.

Ultra-high levels of CO2, i.e., >10,000 ppm, enhance tissue culture growth and offers a relatively simple and inexpensive method to improve plant productivity in vitro. Growth responses employing ultra-high CO2 levels differ considerably in the literature. Unfortunately, various culture vessels and systems have been employed, making comparisons difficult. In this study, the influence of the vessel container size, medium volume, and various CO2 concentrations (0 to 50,000 ppm) was studied on the growth obtained from lettuce and spearmint cultures. All three of these factors influence growth responses from plants cultured in vitro. Vessel types tested included: culture tubes, Magenta containers, 1-quart jars, 0.5-gallon jars, and 1-gallon jars having culture volumes of 55, 365, 925, 1850, and 3700 ml, respectively. Increasing the size of the culture vessel resulted in an increase growth regardless of the CO2 level tested. For example, fresh weight of spearmint increases of >250% can be obtained in by employing a 1-quart jar compared to using a culture tube. Increasing medium volume using various vessel types, especially using high concentrations of CO2, resulted in dramatic growth increases. For example, a >100% increase in fresh weight could be obtained by increasing the medium volume from 50 ml to 100 ml within a 1-quart jar. These studies suggest that plant growth promoted by supplemental CO2 is limited by the culture vessel size and medium volume. Differences in growth responses obtained in past CO2 studies could be related to vessel type and medium volume as well as the CO2 levels employed. Future in vitro studies should consider these factors in the evaluation of the influence of Ultra-high CO2 levels on plant growth. Peculiar growth responses, especially pertaining to rooting and shooting exhibited by cultures grown in ultra-high CO2 levels will also be discussed.

A comparative study was undertaken to determine the influence of lighting, carbohydrate concentrations and ultra-high levels of CO2, i.e., >10,000 ppm, on sterile culture growth. Past CO2-sterile studies have confirmed that elevation of CO2 to as high as 1000 ppm resulted in beneficial growth. Within special constructed chambers, tissue cultures were given a variety of CO2 levels for 12–16 hours/day using artificial lighting and natural sunlight. Several different plants (lettuce, beans, pine) and plant culture types were grown in CO2-enriched environments, ranging from 350 to 50,000 ppm. In almost all cases, plant tissue cultures not only tolerated but exhibited enhanced growth using ultra-high levels of CO2. For example, lettuce cultures were found to grow 2 to 4 times faster under ultra-high CO2. levels than under normal atmospheric CO2 levels, i.e., 350 ppm. Natural sunlight was found to be suitable for sterile culture growth. Modes of administration of CO2 in vitro and gas permeability of various culture vessels are presented.

Young Ian, Silman Robert. Pour un front populaire anglais: 1936 au Daily Herald. In: Matériaux pour l'histoire de notre temps, n°7-8, 1986. L'année 1936 dans le monde, sous la direction de Stéphane Courtois. pp. 36-40.