Author Correction: 3D shear wave velocity model of the crust and uppermost mantle beneath the Tyrrhenian basin and margins

An amendment to this paper has been published and can be accessed via a link at the top of the pape

Flow Assurance in Subsea Pipeline Design - A Case Study of Ghana’s Jubilee and TEN Fields

The increasing exploration and production activities in the offshore Cape Three Point Blocks of Ghana have led to the discovery and development of gas condensate fields in addition to the oil fields which produce significant amount of condensate gas. These discoveries require pipelines to transport the fluids avoiding hydrates and wax formation. This paper focuses on subsea pipeline design using Pipesim software that addresses flow assurance problems associated with transporting condensate gas from the Jubilee and TEN Fields to the Atuabo Gas Processing Plant. It also considered an alternate design that eliminates the need for capacity increase of flowlines for the futuristic highest projected flow rates in 2030. The design comprises of two risers and two flowlines. Hydrate formation temperature was determined to be 72.5 ˚F at a pressure of 3 000 psig. The insulation thickness for flowlines 1 and 2 were determined to be 1.5 in. and 2 in. respectively. The pipe size for flowlines 1 and 2 were determined to be 12 in. and 14 in. respectively. The maximum designed flow rate was determined to be 150 MMSCFD. To meet the highest projected flow rate of 700 MMSCFD in the year 2030 at the processing plant, a 16 in. ID pipeline of 44 km length was placed parallel to the 12 in. ID flowline 1. This parallel pipeline increased the designed flow rate by approximately 4.7 times (705 MMSCFD). The alternate design employs 18 in. and 20 in. ID pipes for flowlines 1 and 2 respectively. Keywords: Condensate Gas; Flowline; Flow Assurance; Hydrate; Pipesi

Enhancing crop productivity through community-based seed multiplication system

Improved quality seeds out-yield farmers' saved seeds significantly. However, the limited availability of such seeds through the conventional seed supply system is due to socio-economic factors and inadequacy of skilled personnel and infrastructure. A community-based seed multiplication system was, therefore, adopted and small seed stocks of soybean, cowpea and yam were distributed to farmer groups in the rural communities in northern Ghana, northern Nigeria and central Togo, respectively, between 1996 and 1999 for further multiplication. An impact assessment after 4 years showed a significant ease of farmers' access to improved seeds and development of linkages with pesticide dealers, credit sources, and extension services as a result of opting for this system. Quality of farmers' saved seeds had improved and farmers' yield had increased over 90 per cent. Extra incomes earned were used to purchase household items, and part invested in transport businesses and rearing of small ruminants as well as in human capital such as paying children's school fees and family hospital bills and meeting other social responsibilities. This system was, therefore, effective in diffusing improved seeds and associated technologies and services to many more farmers and communities within a very short time to improve their socio-economic status.Les graines de qualité améliorée dépassaient considérablement en rendement les graines gardées par les agriculteurs. Cependant, la disponibilité de telles graines par le système conventionnel de provision de graine est limitée en raison de facteurs socio-économiques, l'insuffisance de personnel qualifié et l'infrastructure. Un système de multiplication de graine basé à la communauté était donc adopté et une petite quantité de stocks de graine de soja, de dolique et d'igname étaient distribués aux groupes d'agriculteurs dans les communautés rurales dans le nord du Ghana, le nord du Nigéria et le centre du Togo respectivement entre les années 1996 et 1999 pour de multiplication davantage. L'évaluation d'impact entreprise après quatre années montrait une aisance considérable avec laquelle les agriculteurs avaient accès aux graines améliorées et aux liens de développement avec les marchands de pesticide, les lignes de crédit et les services de vulgarisation agricole à la suite d' opter pour ce système. La qualité de graines gardées par les agriculteurs avait amélioré et les rendements d'agriculteurs avaient augmenté plus de 90%. Les suppléments de revenus gagnés étaient dépensés pour les articles ménagers, et une partie du revenun était investie en entreprises de transport et en élévage de petits ruminants ainsi qu'en ressources humaines telles que le paiement de frais de scolarité de la jeunesse, les factures hospitalières et pour régler d'autres responsabilités sociales. Ce système était donc efficace pour la distribution de graines améliorées et la vulgarisation de services et de technologies liées à l'agriculture à beaucoup plus d'agriculteurs et aux communautés dans très peu de temps pour améliorer leur situation socio-économique. Ghana Journal of Agricultural Science Vol. 39 (2) 2006: pp. 181-18

Seed systems smallholder farmers use

Seed can be an important entry point for promoting productivity, nutrition and resilience among smallholder farmers. While investments have primarily focused on strengthening the formal sector, this article documents the degree to which the informal sector remains the core for seed acquisition, especially in Africa. Conclusions drawn from a uniquely comprehensive data set, 9660 observations across six countries and covering 40 crops, show that farmers access 90.2 % of their seed from informal systems with 50.9 % of that deriving from local markets. Further, 55 % of seed is paid for by cash, indicating that smallholders are already making important investments in this arena. Targeted interventions are proposed for rendering formal and informal seed sector more smallholder-responsive and for scaling up positive impacts

The built environment element of economic development in post conflict response in Indonesia

The recent violent communal conflicts events at the end of 1990s in Indonesia has appointed to the importance of relationship within the community and linked to the role of economic sector and built environment. This paper presents some findings from interviews with four groups of stakeholders related to urban development on a recent study in the context of the communal conflict that occurred on three cases: Solo (Central Java), Poso (Central Sulawesi), and Sambas (West Kalimantan). The finding suggests that the economic development needs to seriously consider the role of traditional market place and informal sector, as well as urban heritage conservation

Progress towards lymphatic filariasis elimination in Ghana from 2000-2016: Analysis of microfilaria prevalence data from 430 communities

Background Ghana started its national programme to eliminate lymphatic filariasis (LF) in 2000, with mass drug administration (MDA) with ivermectin and albendazole as main strategy. We review the progress towards elimination that was made by 2016 for all endemic districts of Ghana and analyze microfilaria (mf) prevalence from sentinel and spot-check sites in endemic districts. Methods We reviewed district level data on the history of MDA and outcomes of transmission assessment surveys (TAS). We further collated and analyzed mf prevalence data from sentinel and spot-check sites. Results MDA was initiated in 2001–2006 in all 98 endemic districts; by the end of 2016, 81 had stopped MDA after passing TAS and after an average of 11 rounds of treatment (range 8–14 rounds). The median reported coverage for the communities was 77–80%. Mf prevalence survey data were available for 430 communities from 78/98 endemic districts. Baseline mf prevalence data were available for 53 communities, with an average mf prevalence of 8.7% (0–45.7%). Repeated measurements were available for 78 communities, showing a steep decrease in mean mf prevalence in the first few years of MDA, followed by a gradual further decline. In the 2013 and 2014 surveys, 7 and 10 communities respectively were identified with mf prevalence still above 1% (maximum 5.6%). Fifteen of the communities above threshold are all within districts where MDA was still ongoing by 2016. Conclusions The MDA programme of the Ghana Health Services has reduced mf prevalence in sentinel sites below the 1% threshold in 81/98 endemic districts in Ghana, yet 15 communities within 13 districts (MDA ongoing by 2016) had higher prevalence than this threshold during the surveys in 2013 and 2014. These districts may need to intensify interventions t

Serological and PCR-based markers of ocular Chlamydia trachomatis transmission in northern Ghana after elimination of trachoma as a public health problem

Background Validation of elimination of trachoma as a public health problem is based on clinical indicators, using the WHO simplified grading system. Chlamydia trachomatis (Ct) infection and anti-Ct antibody responses (anti-Pgp3) have both been evaluated as alternative indicators in settings with varying levels of trachoma. There is a need to evaluate the feasibility of using tests for Ct infection and anti-Pgp3 antibodies at scale in a trachoma-endemic country and to establish the added value of the data generated for understanding transmission dynamics in the peri-elimination setting. Methodology/Principal findings Dried blood spots for serological testing and ocular swabs for Ct infection testing (taken from children aged 1–9 years) were integrated into the pre-validation trachoma surveys conducted in the Northern and Upper West regions of Ghana in 2015 and 2016. Ct infection was detected using the GeneXpert PCR platform and the presence of anti-Pgp3 antibodies was detected using both the ELISA assay and multiplex bead array (MBA). The overall mean cluster-summarised TF prevalence (the clinical indicator) was 0.8% (95% CI: 0.6–1.0) and Ct infection prevalence was 0.04% (95%CI: 0.00–0.12). Anti-Pgp3 seroprevalence using the ELISA was 5.5% (95% CI: 4.8–6.3) compared to 4.3% (95%CI: 3.7–4.9) using the MBA. There was strong evidence from both assays that seropositivity increased with age (p<0.001), although the seroconversion rate was estimated to be very low (between 1.2 to 1.3 yearly events per 100 children). Conclusions/Significance Infection and serological data provide useful information to aid in understanding Ct transmission dynamics. Elimination of trachoma as a public health problem does not equate to the absence of ocular Ct infection nor cessation in acquisition of anti-Ct antibodies