Updated CPT-based p–y formulation for laterally loaded piles in cohesionless soil under static loading

The p–y method is currently the most popular design method to predict the response of piles to lateral load. The authors had previously used numerical methods to develop a cone penetration test (CPT)-based p–y formulation for piles in sand and this has subsequently been shown by independent verification to show considerable promise. This paper addresses some of the uncertainties associated with the original p–y formulation by examining the influence of pile bending stiffness, the presence of a water table, the cross-sectional shape of the pile and soil non-homogeneities. Numerical experiments are presented examining these four effects and lead to an updated proposal for a CPT-based p–y formulation. This formulation, which is consistent with the original proposal, is validated against three-dimensional finite-element calculations and data obtained from a full-scale offshore monopile foundation supporting a wind turbine

Numerical derivation of CPT-based p-y curves for piles in sand

The formulations for the lateral load-displacement (p-y) springs conventionally used for the analysis of laterally loaded piles have been based largely on the back-analysis of the performance of small-scale instrumented piles subjected to lateral load. Although such formulations have been employed with much success in industry, their applicability to large-diameter piles, such as those used to support offshore wind turbines, is uncertain and has necessitated further research in this area. Moreover, with the growth in popularity of in-situ cone penetration tests (CPTs), there are demands for a theoretically supported direct method that can enable the derivation of p-y curves from the CPT end resistance (q c). In this paper, a numerical derivation of CPT-based p-y curves applicable to both small- and large-diameter laterally loaded single piles in sand is presented. Three-dimensional finite-element analyses are performed using a non-linear elasto-plastic soil model to predict the response of single piles in sand subjected to lateral loads. The corresponding CPT q c profile is derived using the same soil constitutive model by way of the cavity expansion analogue. An extensive series of computations of the lateral pile response and CPT q c values is then employed to formulate a direct method of constructing p-y curves from CPT q c values. The proposed method is shown to be generally consistent with existing empirical correlations and to provide good predictions in relation to the measurements obtained during lateral load tests on instrumented piles in an independent case study

Mothers' voices: hearing and assessing the contributions of 'birth mothers' to the development of social work interventions and family support

This paper focuses on interviews with ‘birth mothers’ who experienced successive losses of their children to public care in one local area of London, England. Interviews were conducted during a project partnership between a London borough and university staff, aiming to provide a localised, pilot support initiative which responded to mothers’ viewpoints. To ‘hear’ mothers’ own voices more clearly, we analysed interview transcripts using a methodology which separates out elements of how the interviewee tells her story, how she speaks about herself and about her relationships, taking into account surrounding social complexities and researchers’ reactions to the story. To explain how professionals could subsequently draw upon these ‘mothers’ voices’ for a pilot support initiative, we identify some key messages for professionals from these interviews, including: women wanting clear and honest communication between themselves and workers, and between staff; women often feeling ‘let down’ by professional procedures and court processes that were moving too fast for them to keep up; women wanting to be treated with more respect. Women respected some professionals but not others and this seemed to relate partly to personalities. Some mothers experienced being ‘left alone’ or ‘abandoned’ to deal with the aftermath of children’s removal and/or adoption

Adult midgut expressed sequence tags from the tsetse fly Glossina morsitans morsitans and expression analysis of putative immune response genes

BACKGROUND: Tsetse flies transmit African trypanosomiasis leading to half a million cases annually. Trypanosomiasis in animals (nagana) remains a massive brake on African agricultural development. While trypanosome biology is widely studied, knowledge of tsetse flies is very limited, particularly at the molecular level. This is a serious impediment to investigations of tsetse-trypanosome interactions. We have undertaken an expressed sequence tag (EST) project on the adult tsetse midgut, the major organ system for establishment and early development of trypanosomes. RESULTS: A total of 21,427 ESTs were produced from the midgut of adult Glossina morsitans morsitans and grouped into 8,876 clusters or singletons potentially representing unique genes. Putative functions were ascribed to 4,035 of these by homology. Of these, a remarkable 3,884 had their most significant matches in the Drosophila protein database. We selected 68 genes with putative immune-related functions, macroarrayed them and determined their expression profiles following bacterial or trypanosome challenge. In both infections many genes are downregulated, suggesting a malaise response in the midgut. Trypanosome and bacterial challenge result in upregulation of different genes, suggesting that different recognition pathways are involved in the two responses. The most notable block of genes upregulated in response to trypanosome challenge are a series of Toll and Imd genes and a series of genes involved in oxidative stress responses. CONCLUSIONS: The project increases the number of known Glossina genes by two orders of magnitude. Identification of putative immunity genes and their preliminary characterization provides a resource for the experimental dissection of tsetse-trypanosome interactions

Verification of numerically derived CPT based p-y curves for piles in sand

This paper examines the potential of a numerically derived CPT-based formulation for p-y curves in sand (Suryasentana & Lehane 2014) to predict the response observed in lateral load tests conducted on six piles in four different sand deposits. A summary of the methodology employed in the derivation of this formulation is first described before presenting information related to each of the case histories examined. The lateral load displacement data measured in these case histories are shown to compare well with predictions obtained using the p-y formulation. This agreement should encourage further refinement of the formulation and ultimately the direct use of CPT qc profiles for the analysis of laterally loaded piles in sand

International Glossina Genome Initiative 2004-2014: a driver for post-genomic era research on the African continent

Human African trypanosomiasis (HAT), also known as sleeping sickness, is a neglected disease that impacts 70 million people distributed over 1.55 million km2 in sub- Saharan Africa and includes at least 50% of the population of theDemocratic Republic of the Congo [1]. Trypanosoma brucei gambiense accounts for more than 98% of the infections in central and West Africa, the remaining infections being from Trypanosoma brucei rhodesiense in East Africa [2]. The parasites are transmitted to the hosts through the bite of an infected tsetse fly. Disease control is challenging as there are no vaccines, and effective, easily delivered drugs are still lacking. Treatment invariably involves lengthy hospitalization, with both medical and socioeconomic consequences.Web of Scienc

Assessing the functional performance of post-call hospital doctors using a Nintendo Wii.

Sleep deprivation is an established part of the working life for Non-Consultant Hospital Doctors (NCHDs) in Ireland. Concern exists about the effect of extended NCHD work hours. We utilised a Nintendo Wii to evaluate motor function of NCHDs both prior to their on-call shift and the day afterwards. Data was exported to SPSS ver. 15 for statistical analysis with p \u3c 0.05 considered significant. A total of 72 NCHDs were invited to participate in this study. There was a 62.5% (45) rate of follow-up. Overall 27 (60%) NCHDs were on medical call, with 18 (40%) on surgical call. There was no statistically significant difference between NCHDs pre-and post-call motor assessment scores. The majority of study participants (75.5%, n = 34) had four or more hours sleep. On-call duty allows for a greater than anticipated amount of sleep per on-call shift and therefore has a negligible effect on the motor skills of medical staff

Sheep productivity in an Astrebla grassland of south-west Queensland

A grazing study conducted between 1979 and 1983 assessed the seasonal trends of ewe productivity in Astrebla grassland in southwestern Queensland. This study was designed originally to compare productivity on two pastures with different compositions, however, these differences in pastures composition were not achieved. Large differences in liveweight, wool growth and reproductive performance occurred between years in response to differences in pasture growth resulting from large variation in the seasonal incidence of rainfall. Rainfall effective for plant growth, both forbs and grasses, resulted in a high quality diet which resulted, in turn, in increased sheep productivity. Reproductive performance was particularly sensitive to the quality of the ewes diet around the time of lambing through the effect of diet quality on lamb survival and growth rate. It is suggested that the effect of rainfall on reproductive performance is of greater importance than the yield of forbs present in the pasture

Tsetse control and Gambian sleeping sickness ; implications for control strategy

Background Gambian sleeping sickness (human African trypanosomiasis, HAT) outbreaks are brought under control by case detection and treatment although it is recognised that this typically only reaches about 75% of the population. Vector control is capable of completely interrupting HAT transmission but is not used because it is considered too expensive and difficult to organise in resource-poor settings. We conducted a full scale field trial of a refined vector control technology to determine its utility in control of Gambian HAT. Methods and Findings The major vector of Gambian HAT is the tsetse fly Glossina fuscipes which lives in the humid zone immediately adjacent to water bodies. From a series of preliminary trials we determined the number of tiny targets required to reduce G. fuscipes populations by more than 90%. Using these data for model calibration we predicted we needed a target density of 20 per linear km of river in riverine savannah to achieve >90% tsetse control. We then carried out a full scale, 500 km(2) field trial covering two HAT foci in Northern Uganda to determine the efficacy of tiny targets (overall target density 5.7/km(2)). In 12 months, tsetse populations declined by more than 90%. As a guide we used a published HAT transmission model and calculated that a 72% reduction in tsetse population is required to stop transmission in those settings. Interpretation The Ugandan census suggests population density in the HAT foci is approximately 500 per km2. The estimated cost for a single round of active case detection (excluding treatment), covering 80% of the population, is US$433,333 (WHO figures). One year of vector control organised within the country, which can completely stop HAT transmission, would cost US$42,700. The case for adding this method of vector control to case detection and treatment is strong. We outline how such a component could be organised

Prospects for developing odour baits to Control Glossina fuscipes spp., the major vector of human African trypanosomiasis

We are attempting to develop cost-effective control methods for the important vector of sleeping sickness, Glossina fuscipes spp. Responses of the tsetse flies Glossina fuscipes fuscipes (in Kenya) and G. f. quanzensis (in Democratic Republic of Congo) to natural host odours are reported. Arrangements of electric nets were used to assess the effect of cattle-, human- and pig-odour on (1) the numbers of tsetse attracted to the odour source and (2) the proportion of flies that landed on a black target (1 x 1 m). In addition responses to monitor lizard (Varanus niloticus) were assessed in Kenya. The effects of all four odours on the proportion of tsetse that entered a biconical trap were also determined. Sources of natural host odour were produced by placing live hosts in a tent or metal hut (volumes approximate to 16 m(3)) from which the air was exhausted at similar to 2000 L/min. Odours from cattle, pigs and humans had no significant effect on attraction of G. f. fuscipes but lizard odour doubled the catch (P<0.05). Similarly, mammalian odours had no significant effect on landing or trap entry whereas lizard odour increased these responses significantly: landing responses increased significantly by 22% for males and 10% for females; the increase in trap efficiency was relatively slight (5-10%) and not always significant. For G. f. quanzensis, only pig odour had a consistent effect, doubling the catch of females attracted to the source and increasing the landing response for females by similar to 15%. Dispensing CO2 at doses equivalent to natural hosts suggested that the response of G. f. fuscipes to lizard odour was not due to CO2. For G. f. quanzensis, pig odour and CO2 attracted similar numbers of tsetse, but CO2 had no material effect on the landing response. The results suggest that identifying kairomones present in lizard odour for G. f. fuscipes and pig odour for G. f. quanzensis may improve the performance of targets for controlling these species