Pushdown resistance as a measure of robustness in progressive collapse analysis

This paper presents a technique termed ‘pushdown analysis’ that can be used to investigate the robustness of building systems by computing residual capacity and establishing collapse modes of a damaged structure. The proposed method is inspired by the pushover method commonly used in earthquake engineering. Three variants of the technique, termed uniform pushdown, bay pushdown and incremental dynamic pushdown, are suggested and exercised using nonlinear analysis on 10-story steel moment frames designed for moderate and high levels of seismic risk. Simulation results show that the frame designed for high seismic risk is more robust than the corresponding one designed for moderate seismic risk. The improved performance is attributed to the influence of seismic detailing, specifically, the presence of reduced beam sections and stronger columns. It is shown that the dynamic impact factors associated with column removal are significantly lower than the commonly used value of 2.0 and are in line with lower values in the guidelines recently proposed by the US Department of Defense. The study suggests that seismic ‘fuses’ can play a role in the design for robustness and a discussion of the implications of this observation is provided.     

Iron, folate, and vitamin B12 stores among pregnant women in a rural area of Haryana State, India

BACKGROUND: Iron, folate, and vitamin B12 deficiencies have adverse effects on pregnancy outcome. In India, data on the concomitant prevalence of these deficiencies among pregnant women are meager. OBJECTIVE: We conducted a community-based study to assess the prevalence of deficiencies of iron, folate, and vitamin B12 among pregnant women in a rural block of Haryana State. METHODS: The study was approved by the ethics committee of the All India Institute of Medical Sciences, New Delhi. A total of 283 pregnant women were enrolled in the study. After oral informed consent had been obtained from the women, blood was drawn from the antecubital vein for estimation of the levels of serum ferritin by enzyme-linked immunosorbent assay (levels < 12 ng/ mL were considered as indicative of poor iron stores); serum folate was determined by radioimmunoassay (levels <3 ng/mL were considered as indicative of poor folate stores); and serum vitamin B12 was estimated by the microbiologic method (levels < 200 pg/mL were considered as indicative of poor vitamin B12 stores). RESULTS: The results indicated that 67.7%, 26.3%, and 74.1% of the women had poor iron, folate, and vitamin B12 stores, respectively. Concomitant deficiencies of iron, folate, and vitamin B12 occurred in 16.2% of the women. We found that 59.9% of the women were consuming less than 75% of the recommended daily caloric allowance (2175 kcal), indicating an overall poor food intake. This could be one of the predominant reasons for poor iron, folate, and vitamin B12 stores among the women. CONCLUSIONS: Our findings suggest that apart from iron and folate, vitamin B12 deficiencies may play an important role in causing anemia.     

Has the increase in world-wide openness to trade worsened global income inequality?

This article contributes to our understanding of the relationship between globalization and world income inequality by analyzing the trend in global inequality for the period 1960–1989. Using Penn World Tables data and time-series econometric techniques, it analyzes how the increase in worldwide openness to trade has been related to global income inequality during this period. When differential population growth rates among the countries are taken into account, the results indicate that (i) global income inequality exhibited a downward trend between 1960 and 1989, and (ii) while there is a positive relationship between inequality and openness, the relationship is not statistically significant. Received: 22 December 2000 / Accepted: 29 May 2001     

Sustained local delivery of heparin to the rabbit arterial wall with an electroporation catheter

Since the rapid expansion of managed care coupled with dramatic reductions in lengths of inpatient stay, there is widespread concern that the emphasis on cost containment is eclipsing attention to patient care. The present study was undertaken to evaluate speculations that the majority of short-stay (less than 48 hours) admissions to a psychiatric inpatient service at a large teaching hospital in the midwestern United States consisted of public pay patients who were rapidly transferred to area state hospitals. Using two cases mix measures, severity of illness and changes in acuity and clinical outcomes of a sample of short-stay (n = 77) and longer stay (n = 145) admissions were compared. Short-stay admissions, although similar to longer stay patients in terms of demographics, Axis I diagnosis, payer status, and appropriateness of admission, are clinically distinct. The use of nonhospital alternatives in treating a subsample of suicidal patients and the implications for improved mental health services delivery are discussed.     

Status of iodine deficiency in selected blocks of Kangra District, Himachal Pradesh

Using polymerase chain reaction single strand conformational polymorphism (PCR-SSCP) and EB staining technique, paraffin-embeded sections of 20 hydatidiform mole and 4 choriocarcinoma were detected in the exons 5 and 8 of p53 gene. The results showed that mutations of p53 gene were 0/9 in the normal chorionic villi, 6/20 (30%) in hydatidiform mole and 3/4 in choriocarcinoma. This study suggests that mutations of p53 gene may be an important event in human gestational trophoblastic neoplastigenesis and its progression.     

Postnatal survival and growth of mouse irradiated in utero with low dose

In order to investigate radiation risks associated with low dose and low dose-rates, pregnant Swiss albino mice were exposed to gamma rays, 0.80 Gy from a cobalt-60 source at two different dose-rates (0.0795 and 0.0012 Gy/min) on 18 day post conception. In females exposed to lower dose-rate (0.0012 Gy/min), litter size was found to be decreased, while those exposed to higher dose-rate (0.0795 Gy/min), it remained unaltered. In both groups, appearance of fur and development of complete fur were delayed, whereas gait was delayed only in higher dose-rate group. Male offspring exhibited a biphasic mode of weight loss, while female offspring after an initial weight loss at 1 week, displayed a continuous recovery, but could not attain the normal weight till 12 weeks of age. It appears that higher dose-rate is more effective in delaying the appearance of physiological markers and weight loss, while in terms of litter size lower dose-rate (0.0012 Gy/min) is more effective.     

The yields of extracted leaf protein from lucerne (Medicago sativa L.)

The effects of fertilisers, frequency of cutting, row spacing and simazine on the yields of dry matter and extractable protein from lucerne (Medicago sativa L.) were studied using the laboratory-scale pulper and press. Between 40 and 65% protein nitrogen was extractable; extractability was not affected by the various treatments but altered with season. Lucerne responded with increased yields of dry matter and extractable protein to fertilisers, simazine (35 g/ha) and rows spaced at 30.5 cm. Six or 8 harvests were found to give greater yields than 5 harvests in 180 days. The annual yields of extractable protein reached 3100 kg/ha and it is felt that better control of pests could lead to even greater yields.     

Micellization of three-block copolymer poly[styrene-b-(ethene-co-butene)-b-styrene] in mixed solvents of tetrahydrofuran/ethanol

The behaviour of dilute solutions of a three-block copolymer poly[styrene-b-(ethene-co-butene)-b-styrene] in mixtures of tetrahydrofuran (THF)/ethanol was studied using viscometry, osmometry and light scattering. In solutions with a lower ethanol content the copolymer dissolved, but in solutions with a higher ethanol content it became associated, to form spherical micelles with cores composed of middle (aliphatic) blocks. Between the molecular and micellar solutions a region of the so-called anomalous micellization was described. Micelles in mixtures with a higher ethanol content were stabilized by means of fast electrons, isolated and characterized in THF solutions.