Seismic behavior of circular reinforced concrete bridge columns under combined loading including torsion

Reinforced concrete (RC) columns of skewed and curved bridges with unequal spans and column heights can be subjected to combined loading including axial, flexure, shear, and torsion loads during earthquakes. The combination of axial loads, shear force, and flexural and torsional moments can result in complex failure modes of RC bridge columns. This study carried out experimental and analytical studies to investigate the seismic performance of circular RC columns under combined loading including torsion. The main variables considered here were (i) the ratio of torsion-to-bending moment (T/M), (ii) the ratio of bending moment-to-shear (M/V) or shear span (H/D), and (iii) the level of detailing for high and moderate seismicity (high or low spiral ratio). In particular, the effects of the spiral reinforcement ratio and shear span on strength and ductility of circular RC columns under combined loading were addressed. In addition, the effects of torsional loading on the bending moment-curvature, ductility, and energy dissipation characteristics were also considered. The analytical investigation examined the development of existing models for flexure and pure torsion. Interaction diagrams between bending, shear and torsional loads were established from a semi-empirical approach. A damage-based design approach for circular RC columns under combined loads was proposed by decoupling damage index models for flexure and torsion. Experimental and analytical results showed that the progression of damage was amplified by an increase in torsional moment. An increase in the transverse spiral reinforcement ratio delayed the progression of damage and changed the torsional-dominated behavior to flexural-dominated behavior under combined flexural and torsional moments --Abstract, page iii

Hatchery production of Black-lip pearl oyster spat in the Andaman and Nicobar Islands: a success story

The lustrous black pearls produced by the black-lip pearl oysler Pinctada margaritifera in the inner surface its two shells have become one of the most valuable pearls on earth with prices ranging from a minimum of 100 US$and to a maximum of 10,000 US$ per pearl, in the case of those at exceptional and rare quality. Through the production of black pearls from Pinctada margaritifera, the island country of Tahili became the global leader in this business controlling 28.8% of the world market

Endothelial progenitor cell biology in disease and tissue regeneration

Endothelial progenitor cells are increasingly being studied in various diseases ranging from ischemia, diabetic retinopathy, and in cancer. The discovery that these cells can be mobilized from their bone marrow niche to sites of inflammation and tumor to induce neovasculogenesis has afforded a novel opportunity to understand the tissue microenvironment and specific cell-cell interactive pathways. This review provides a comprehensive up-to-date understanding of the physiological function and therapeutic utility of these cells. The emphasis is on the systemic factors that modulate their differentiation/mobilization and survival and presents the challenges of its potential therapeutic clinical utility as a diagnostic and prognostic reagent

Biometric relationships of the black winged pearl oyster, Pteria penguin (Roding, 1798) from Andaman and Nicobar Islands

The dimensional biometric relationships including that of length-weight was studied in the black winged oyster Pteria penguin, which is a candidate species for mariculture. During the life span of the winged oysters, growth in length and weight was initially 40-100 mm dorso-ventral measurement (DVM), positively allometric and subsequently became isometric (100-160 mm DVM) and finally reverted back to allometry (160-220 mm DVM). This is attributed to the increase in visceral mass of animals corresponding to gonadal maturation during the size range 100 - 160 mm DVM. In larger sized P. penguin, increase in shell length is more predominant as evidenced by large proportion of non-nacreous layer at the outer edge of the shell. There was no parallel increase in visceral mass resulting in allometry. All dimensional relationships were positive in relation to DVM; however the relationship between DVM and hinge length did not show significant R2 values (p>0.05) in all the size groups. This was mainly because, the tips of the hinge and ear were found to be broken at both the ends. Therefore, notch length is proposed as a better predictor of DVM in large hinged pterid oysters. Unlike other pterid pearl oysters, the thickness - DVM ratio showed a decline with size, indicating that bead seeding programmes can be initiated at early stage

A convenient and eco-friendly one-pot synthesis of 3-triazolyl-2-iminochromenes and investigation of their antioxidant properties

A simple, green and efficient procedure for the synthesis of highly functionalized 3-triazolyl-2-iminochromenes by using a one-pot three component reaction of 2-azido acetonitrile, phenylacetylene and salicylaldehyde in water using CuI/K2CO3 is described. The present protocol offers advantages like high atom economy, simple methodology, shorter reaction time, easy product isolation, no chromatographic purification and avoidance of environmentally hazardous solvents. Compounds 4a-d, 4g-h and 6a-b have been investigated for antioxidant activity. Compound 4c is found to be the most active among the series showing high reducing power and free radical scavenging activity

Mabe pearl production: a technology for A & N Islands' development

The marine pearling industry is diverse, with a wide range of cultured pearls and several levels of entrepreneurs ranging from villagers who collect spat from natural beds to large entrepreneurs, who have made huge investments in pearl production and trade

Economic evaluation of implementing a rapid point-of-care screening test for the identification of hepatitis C virus under National Viral Hepatitis Control Programme in Tamil Nadu, South India

Introduction: Viral hepatitis is a crucial public health problem in India. Hepatitis C virus (HCV) elimination is a national priority and a key strategy has been adopted to strengthen the HCV diagnostics services to ensure early and accurate diagnosis. Methods: To conduct an economic evaluation of implementing a rapid point-of-care screening test for the identification of HCV among the selected key population under the National Viral Hepatitis Control Programme in Tamil Nadu, South India. Economic evaluation of a point-of-care screening test for HCV diagnosis among the key population attending the primary health care centers. A combination of decision tree and Markov model was developed to estimate cost-effectiveness of point-of-care screening test for HCV diagnosis at the primary health care centers. Total costs, quality-adjusted life years (QALYs) of the intervention and comparator, and incremental cost-effectiveness ratio (ICER) were calculated. The model parameter uncertainties which would influence the cost-effectiveness outcome has been evaluated by one-way sensitivity analysis and probabilistic sensitivity analysis. Results: When compared to the tertiary level diagnostic strategy for HCV, the point-of-care screening for selected key population at primary health care level results in a gain of 57 undiscounted QALYs and 38 discounted QALYs, four undiscounted life years and two discounted life years. The negative ICER of the new strategy indicates that it is less expensive and more effective compared with the current HCV diagnosis strategy. Conclusions: The proposed strategy for HCV diagnosis in the selected key population in Tamil Nadu is dominant and cost-saving compared to the current strategy

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700