Residual Strength of Liquefied Sand: Laboratory vs. Field Measurements

Determining the residual strength of liquefied sand is essential for estimating post-earthquake stability of vulnerable earth structures, or calculating runout of liquefaction flow slides. Current practice is to select values from a database of back-calculated residual strengths from failure case histories, which have been related to representative penetration test resistance numbers in the failed materials. Given the uncertainties involved, it is desirable to compare the field data with laboratory tests under controlled conditions. This paper describes residual strength measurements for a uniform fine sand using two recently-developed tests designed to impose large strains and strain rates: a modified triaxial test in which a metal coupon is dragged through the liquefied sample by an external dead weight, and a ring shear device which can impose constant rates of strain on the liquefied sand. In all cases, a stress-thinning behavior is observed; however, coupon movement through the liquefied sand is basically laminar, representing conditions in the interior of a flowing mass, while the rotating ring creates a well-defined contact shear band and higher resistance, which might be considered more representative of flow at the base of a sliding mass. Comparison with back-calculated field values shows that coupon residual strengths plot at the lower bound, and ring shear results at the upper bound, of backcalculated field values

The Union and Médecins Sans Frontières approach to operational research.

Operational research (OR) has become a hot topic at national meetings, international conferences and donor fora. The International Union Against Tuberculosis and Lung Disease (The Union) and Médecins Sans Frontières (MSF) Operational Centre Brussels strongly promote and implement OR with colleagues in low- and middle-income countries. Here we describe how the two organisations define OR, and explain the guiding principles and methodology that underpin the strategy for developing and expanding OR in those countries. We articulate The Union's and MSF's approach to supporting OR, highlighting the main synergies and differences. Then, using the Malawi National Tuberculosis Control Programme as an example, we show how OR can be embedded within tuberculosis control activities, leading to changes in policy and practice at the national level. We discuss the difficult, yet vitally important, issue of capacity building, and share our vision of a new paradigm of product-related training and performance-based OR fellowships as two ways of developing the necessary skills at country level to ensure research is actually performed. Finally, we highlight the need to consider and incorporate into practice the ethical components of OR. This is a key moment to be involved in OR. We are confident that in partnership with interested stakeholders, including the World Health Organization, we can stimulate the implementation of quality, relevant OR as an integral part of health service delivery that in turn will lead to better health for people, particularly for those living in the poorer parts of the world

On-farm Experiments with Millet in Niger: Crop Establishment, Yield Loss Factors and Economic Analysis

Results of farm-level experiments with pearl millet are reported from four villages in semi-arid Niger in 1982 and 1983. Crop establishment, yield loss factors (insects, diseases, striga) and economics of new practices were studied in a randomized design which included density, fertility, cultivar, and intercropping with cowpea as treatments. Improved cultivars did not establish significantly better than local ones, but fertilizer occasionally improved establishment. Incidence of yield loss factors was low, and only small effects of cultivar and fertilizer were seen. Fertilizer increased grain yields of the local cultivar by as much as 153%. The use of fertilizer and improved cultivars increased grain yields by as much as 171% over an unfertilized local millet. Even without government subsidies, fertilizer use was profitable for 56% of farmers on all cultivars. In general, fertilizers and improved cultivars had a small positive impact on profitability, with little adverse impact on grain yield variability, so that they could be recommended to farmers with some prospect of success. The intercropping treatment failed in both years, and would have to be modified before extensio

PR Professionals' Technology Use: Emotional, Financial, and Professional Ramifications

This study examined Information and communication technologies (ICT) use by public relations practitioners and its influence on work-life conflict, income, and professional outlook through a random national survey (n = 820) of Public Relations Society of America (PRSA) members. We found that practitioners primarily use direct media more than network-building media and visual media. ICT use (direct and visual media use) was a significant predictor of time-based work-life conflict. Some types of ICT use significantly enhance practitioners’ income and influence their professional outlook

Nutrient and structural carbohydrate partitioning in pearl millet

Pennisetum glaucum cv. CIVT grown on a Labucheri soil at Sadoré, Niger in 1989-90 was given 15 or 45 kg N and 4.4 or 17.4 kg P/ha. Increased N rate increased total DM by 13%, N uptake by 63% and P uptake by 29%. Increased P rate increased total DM by 100%, N uptake by 80% and P uptake by 140%. In 1989, with adequate rainfall, grain yield was 0.6 t/ha with 15 kg N/ha and 0.9 t with 45 kg N, whereas in 1990, with low rainfall, grain yield was lower and unaffected by N rate. Grain yield was higher with the higher P rate in both years. N concentration in the stover was increased by increased N rate and decreased by the higher P rate. Plant P concentration was higher at the higher P rate. Mean total DM yield was 2.75 t/ha, partitioned into grain (18%); animal feed consisting of chaff, immature panicles, upper stover and tillers (41%); and middle and lower stover components for soil conservation (41%). Partitioning was not affected by fertilizer rate. Of the total N (33.4 kg/ha) and P (5.2 kg/ha) uptake, 32 and 40% were contained in grain, 41 and 40% in animal feed, and 27 and 20% in components for soil conservation, respectivel

Quantification of temporal fault trees based on fuzzy set theory

© Springer International Publishing Switzerland 2014. Fault tree analysis (FTA) has been modified in different ways to make it capable of performing quantitative and qualitative safety analysis with temporal gates, thereby overcoming its limitation in capturing sequential failure behaviour. However, for many systems, it is often very difficult to have exact failure rates of components due to increased complexity of systems, scarcity of necessary statistical data etc. To overcome this problem, this paper presents a methodology based on fuzzy set theory to quantify temporal fault trees. This makes the imprecision in available failure data more explicit and helps to obtain a range of most probable values for the top event probability

Grain growth of Pennisetum glaucum (L.) R.Br. under well-watered and drought-stressed conditions

The objective of this study was to investigate the possibility of relationships between grain growth parameters and drought response. Grain growth parameters of more than 70 millet lines were assessed under well-watered and postflowering drought-stress conditions in two field trials at the ICRISAT Sahelian Center, Sadoré, Niger. All the grain growth parameters based on thermal time varied more than two-fold between lines in both moisture environments. Single grain mass of the lines ranged from 4.3–10.9 mg under well-watered conditions and 3.4–9.4 mg under drought stress. When averaged across trials, 51% of the accounted variance of final grain mass could be explained by differences in the grain growth rate under well-watered conditions, while differences in the duration of the linear grain growth phase accounted for 37% of the variation in final grain mass. Drought stress reduced the linear grain growth phase and, as a consequence, reduced final grain mass by up to 25%. Lines with long grain filling periods under well-watered conditions had larger reductions in the grain filling period and in final grain mass under stress. In general, there was little effect of drought stress on the grain growth rate. However, because of the negative correlation of grain growth rate and linear grain growth phase, lines with higher grain growth rates in well-watered conditions had smaller reductions in grain filling period under stress. Grain growth rate accounted with 38% for the major part of the variation in grain mass under stress conditions. Grain growth parameters in well-watered and drought-stress conditions were unrelated to drought tolerance as expressed by a drought response index, and were indicators of neither susceptibility nor tolerance to stress. However final grain mass was highly correlated to yield under stress. A feasible risk-reducing strategy in the likelihood of postflowering stress is to select pearl millet lines for drought escape with a high grain growth rate combined with a relatively short grain filling period

Crop physiology and breeding for drought tolerance: research and development

This paper presents an example of the research and development function of a physiology group within a cereal breeding program: an evaluation of the possibility of incorporating selection for tolerance to drought stress during the flowering and grain-filling period in pearl millet. It includes a review of the problem and possible solutions, and a report of two experiments conducted to identify phenotypic characteristics associated with yield differences under stress which could be used as selection criteria in breeding for tolerance. Differences among genotypes in yield under stress during flowering and grain-filling were partitioned into differences in yield potential, drought escape, and droughttolerance; the drought response accounted for more than 40% of the observed yield differences. Phenotypic traits related to yield under stress were divided into those reflecting drought escape and those reflecting droughttolerance. Droughttolerance was found to be primarily expressed in traits relating to the ability to maintain grain numbers under stress (grain number per panicle and per unit area, and grain yield per panicle). Drought escape, in contrast, was expressed in terms of greater grain biomass and higher harvest index. However, the field data also indicated that considerable progress in yield under stress should be possible by selection for earlier flowering and improved yield potential alon

Potential of ToxCast data in the safety assessment of food chemicals

Tox21 and ToxCast are high-throughput in vitro screening (HTS) programmes coordinated by the U.S. National Toxicology Program and the U.S. Environmental Protection Agency, respectively, with the goal of forecasting biological effects in vivo based on bioactivity profiling. The present study investigated whether mechanistic insights in the biological targets of food-relevant chemicals can be obtained from ToxCast results, when the chemicals are grouped according to structural similarity. Starting from the 556 direct additives that have been identified in the ToxCast database by Karmaus et al. (2017), the results showed that, despite the limited number of assays in which the chemical groups have been tested, sufficient results are available within so-called “DNA binding” and “nuclear receptor” target families to profile the biological activities of the defined chemical groups for these targets. The most obvious activity identified was the estrogen receptor (ER)-mediated actions of the chemical group containing parabens and structurally related gallates, as well the chemical group containing genistein and daidzein (the latter particularly towards ERβ as potential health beneficial target). These group effects, as well as the biological activities of other chemical groups, was evaluated in a series of case studies. Overall, the results of the present study suggest HTS data could add to the evidence considered for regulatory risk assessments for food chemicals and to the evaluation of desirable effects of nutrients and phytonutrients. The data will be particularly useful for providing mechanistic information and to fill data gaps with read-across

Management Practices to Increase Yield and Yield Stability of Pearl Millet in Africa

Fertility, soil, and crop management practices that could have an impact on improving millet production in the major millet growing areas of Africa are described. These factors are examined in terms of their potential impact on production and their availability to the resource-poor farmer. Important practices that optimize the use of available water are discussed. If farmers of the semi-arid tropics of West Africa1190improve the fertility of their soils and move from hand tools to using animal traction, increased and stable yields are possible in this drought-prone region