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High-quality soil maps are urgently needed by diverse stakeholders, but errors in existing soil maps are often unknown, particularly in countries with limited soil surveys. To address this issue, we used field soil data to assess the accuracy of seven spatial soil databases (Digital Soil Map of the World, Namibian Soil and Terrain Digital Database, Soil and Terrain Database for Southern Africa, Harmonized World Soil Database, SoilGrids1km, SoilGrids250m, and World Inventory of Soil Property Estimates) using topsoil texture as an example soil property and Namibia as a case study area. In addition, we visually compared topsoil texture maps derived from these databases. We found that the maps showed the correct topsoil texture in only 13% to 42% of all test sites, with substantial confusion occurring among all texture categories, not just those in close proximity in the soil texture triangle. Visual comparisons of the maps moreover showed that the maps differ greatly with respect to the number, types, and spatial distribution of texture classes. The topsoil texture information provided by the maps is thus sufficiently inaccurate that it would result in significant errors in a number of applications, including irrigation system design and predictions of potential forage and crop productivity, water runoff, and soil erosion. Clearly, the use of these existing maps for policy- and decision-making is highly questionable and there is a critical need for better on-site estimates and soil map predictions. We propose that mobile apps, citizen science, and crowdsourcing can help meet this need.

Orientation: Leaders need goodness-of-fit with the context in which they are leading, and coaching is considered an effective strategy to achieve this.Research purpose: To critically problematise current dominant coaching strategies in terms of their underlying worldviews, in order to assess their potential effectiveness and relevance in enhancing context‒leadership goodness-of-fit, given the emerging context faced by leaders.Motivation for the study: The current ever-changing context of leaders requires different thinking, including with regard to coaching. The framework of the coaching landscape, with its associated building blocks, provides the conceptual framework for the review of current coaching strategies. Three dominant worldviews that have historically influenced the thinking in social sciences are employed in this review, namely Newtonian, general systems theory and complexity or chaos (second-order systemic thinking).Research approach/design and method: This was a critical conceptual study aimed at problematising the worldviews informing the currently dominant coaching strategies.Main findings: The problematising of the worldviews underlying the dominant coaching strategies revealed that these strategies are not always informed by a worldview congruent with that demanded by the qualities and features of the world that leaders currently face. There is a pressing need for a coaching strategy informed by a complexity or chaos (second-order systemic) worldview, which better meets the emerging contextual demands and requirements imposed on leaders in practice.Practical/managerial implications: A different coaching strategy, called systemic coaching, is proposed.Contribution/value-add: The proposed systemic coaching strategy is highly suitable to bringing about improved goodness-of-fit between the leader and the emerging context.

The under-performance of supply chains presents a significant hindrance to disease control in developing countries. Stock-outs of essential medicines lead to treatment interruption which can force changes in patient drug regimens, drive drug resistance and increase mortality. This study is one of few to quantitatively evaluate the effectiveness of supply chain policies in reducing shortages and costs. This study develops a systems dynamics simulation model of the downstream supply chain for amikacin, a second-line tuberculosis drug using 10 years of South African data. We evaluate current supply chain performance in terms of reliability, responsiveness and agility, following the widely-used Supply Chain Operation Reference framework. We simulate 141 scenarios that represent different combinations of supplier characteristics, inventory management strategies and demand forecasting methods to identify the Pareto optimal set of management policies that jointly minimize the number of shortages and total cost. Despite long supplier lead times and unpredictable demand, the amikacin supply chain is 98% reliable and agile enough to accommodate a 20% increase in demand without a shortage. However, this is accomplished by overstocking amikacin by 167%, which incurs high holding costs. The responsiveness of suppliers is low: only 57% of orders are delivered to the central provincial drug depot within one month. We identify three Pareto optimal safety stock management policies. Short supplier lead time can produce Pareto optimal outcomes even in the absence of other optimal policies. This study produces concrete, actionable guidelines to cost-effectively reduce stock-outs by implementing optimal supply chain policies. Preferentially selecting drug suppliers with short lead times accommodates unexpected changes in demand. Optimal supply chain management should be an essential component of national policy to reduce the mortality rate. La médiocre performance des chaînes d’approvisionnement constitue un important obstacle à la lutte contre la maladie dans les pays en développement. Les ruptures de stock des médicaments essentiels entraînent une interruption du traitement qui peut contraindre à une modification des régimes posologiques des patients, favoriser la résistance aux médicaments et accroître la mortalité. La présente étude est l’une des rares à évaluer quantitativement l’efficacité des stratégies de la chaîne d’approvisionnement dans le cadre de la réduction des pénuries et des coûts. En se fondant sur les données recueillies au cours de 10 années en Afrique du Sud, l’étude développe un modèle de simulation de la dynamique en aval de la chaîne d’approvisionnement de l’amikacine, un antituberculeux de deuxième intention. Nous évaluons les performances actuelles de la chaîne d’approvisionnement en termes de fiabilité, de réactivité et de rapidité, en suivant le cadre de référence largement utilisé dans la gestion de la chaîne d’approvisionnement. Nous simulons 141 scénarios qui représentent différentes combinaisons de caractéristiques des fournisseurs, de stratégies de gestion des stocks et de méthodes de prévision de la demande afin d’identifier l’ensemble de politiques optimales de gestion au sens de Pareto, politiques qui minimisent aussi bien le nombre de pénuries que le coût total. En dépit de longs délais de livraison des fournisseurs et une demande imprévisible, la chaîne d’approvisionnement de l’amikacine est fiable à 98% et suffisamment rapide pour répondre à une augmentation de 20% de la demande sans occasionner de pénurie. Cependant, on ne peut y parvenir qu’avec un surstockage de l’amikacine à hauteur de 167%, ce qui entraîne des surcoûts considérables. La réactivité des fournisseurs est faible: seulement 57% des commandes sont livrées au dépôt central de médicaments de la province dans un délai d’un mois. Nous identifions trois stratégies de gestion optimale des stocks de sécurité au sens de Pareto. La réduction du délai de livraison des fournisseurs peut produire des résultats optimaux au sens de Pareto, même en l’absence d’autres politiques optimales. La présente étude élabore des directives concrètes et réalisables visant à réduire efficacement les ruptures de stock en mettant en œuvre des politiques optimales dans la chaîne d’approvisionnement. Sélectionner en priorité des fournisseurs de médicaments dont les délais de livraison sont les plus courts permet de s’adapter à des modifications inattendues de la demande. La gestion optimale de la chaîne d’approvisionnement devrait être une composante essentielle de la stratégie nationale visant à réduire le taux de mortalité. 供应链不佳给发展中国家疾病控制带来了严重阻碍。基本药 物短缺会干扰治疗, 导致患者用药方案被迫改变, 增加耐药和 死亡率。鲜有研究定量评估供应链政策在减少短缺和降低成 本方面的有效性, 本研究是其中之一。本研究采用南非的10年 数据, 建立二线抗结核药阿米卡星下游供应链的系统动力学模 拟模型。我们依据广泛应用的供应链运作参考框架, 评估供应 链的可靠性、反应性和灵活性。模拟了141个情境, 体现不同 的供应方特点、库存管理策略和需求预测方法的组合, 确定可 以最大程度减少短缺和总成本的Pareto最优管理政策组合。 虽然供应方前置时间长, 需求难以预测, 阿米卡星的供应链还 是具有98%的可靠性, 其灵活性也足以应对20%的需求增长而 不出现短缺。但上述结构是通过积压库存达167%实现的, 这 也增加了存货成本。供应方的反应性较低：只有57%的订单 在一个月内运到省中心药品仓库。我们发现了三项Pareto最 优安全库存管理政策。在没有其他最优政策的情况下, 仅缩短 供应方前置时间也可以带来Pareto最优结果。本研究产生了 具体、可行的指南, 通过实行最优供应链政策来有成本效益地 减少药品短缺。优先选择前置时间短的药品供应方可以适应 需求的意外变化。最优供应链管理应作为国家降低死亡率政 策的关键组成部分。 El bajo rendimiento de las cadenas de suministro presenta un obstáculo significativo para el control de enfermedades en los países en desarrollo. El agotamiento de las medicinas esenciales conduce a la interrupción del tratamiento, lo que puede forzar cambios en los regímenes farmacológicos del paciente, impulsar la resistencia a los medicamentos y aumentar la mortalidad. Este estudio es uno de los pocos que evalúa cuantitativamente la efectividad de las políticas de la cadena de suministro en la reducción de escasez y costos. Este estudio desarrolla un modelo de simulación de la dinámica de los sistemas de la cadena de suministro para la amikacina, un fármaco de segunda línea contra la tuberculosis usando 10 años de datos sudafricanos. Evaluamos el desempeño actual de la cadena de suministro en términos de confiabilidad, capacidad de respuesta y agilidad, siguiendo el ampliamente usado marco de Referencia de Operación de la Cadena de Suministro. Simulamos 141 escenarios que representan diferentes combinaciones de características de proveedores, estrategias de manejo de inventario y métodos de pronóstico de demanda para identificar el conjunto óptimo de Pareto de políticas de manejo que minimizan conjuntamente el número de periodos de escasez y el costo total. A pesar de los largos plazos de entrega de los proveedores y la demanda impredecible, la cadena de suministro de amikacina es 98% confiable y lo suficientemente ágil como para acomodar un aumento de 20% en la demanda sin escasez. Sin embargo, esto se logra sobrestimando la amikacina en un 167%, lo que conlleva altos costos de almacenamiento. La capacidad de respuesta de los proveedores es baja: solo el 57% de los pedidos se entregan al depósito central de medicamentos de la provincia en un mes. Identificamos tres políticas de manejo de existencias de seguridad del óptimo de Pareto. El corto plazo de entrega del proveedor puede producir resultados óptimos de Pareto incluso en ausencia de otras políticas óptimas. Este estudio produce pautas concretas y procesables para reducir los desabastecimientos de manera costo-efectiva mediante la implementación de políticas óptimas para la cadena de suministro. La selección preferencial de los proveedores de medicamentos con tiempos de entrega cortos acomoda cambios inesperados en la demanda. La gestión óptima de la cadena de suministro debe ser un componente esencial de la política nacional para reducir la tasa de mortalidad.

Currarino syndrome is a rare, autosomal dominant condition of caudal anomalies, usually diagnosed in childhood. Adult presentation is rare and malignant transformation of the associated presacral mass even more so. We report a case of a 60-year-old female diagnosed with a malignant neuroendocrine tumour in the presacral mass in Currarino syndrome and describe the surgical management and pathological findings.

This paper proposes a low-order geometrically exact flexible beam formulation based on the utilization of generic beam shape functions to approximate distributed kinematic properties of the deformed structure. The proposed nonlinear beam shapes approach is in contrast to the majority of geometrically nonlinear treatments in the literature in which element-based—and hence high-order—discretizations are adopted. The kinematic quantities approximated specifically pertain to shear and extensional gradients as well as local orientation parameters based on an arbitrary set of globally referenced attitude parameters. In developing the dynamic equations of motion, an Euler angle parametrization is selected as it is found to yield fast computational performance. The resulting dynamic formulation is closed using an example shape function set satisfying the single generic kinematic constraint. The formulation is demonstrated via its application to the modelling of a series of static and dynamic test cases of both simple and non-prismatic structures; the simulated results are verified using MSC Nastran and an element-based intrinsic beam formulation. Through these examples, it is shown that the nonlinear beam shapes approach is able to accurately capture the beam behaviour with a very minimal number of system states.

Orientation Some recent studies have been published that demonstrated the value of remote sensing night-time lights as descriptors and/or proxies for human activity. Research purpose This article investigated the association between night-time light emissions and gross domestic product (GDP) estimates for South Africa. Motivation for the study Satellite night-lights data seemed to be a useful proxy for economic activity at temporal and geographic scales for which traditional data are of poor quality, are unavailable or only available with a large time lag. Research approach/design and method The article primarily used the remote sensing of night-time light emissions using satellite technologies. The methodology employed in this study involved estimating both a vector error correction modelling (VECM) and autoregressive distributed lag (ARDL) models that map light growth into a proxy for GDP growth. Main findings Both the VECM and ARDL models confirmed a long-term co-integrating relationship between GDP (per capita) and night-time lights (total light intensity), a statistically significant short-term error correction term could, however, not be established through the VECM, but indeed through the ARDL model. Practical/managerial implications The results of the study suggested that satellite remote sensing technologies held much promise and opportunities in terms of the field of Economics and Development. Contribution/value-add This study contributes to our understanding of the spatial and temporal behaviour and trends in economic activity. It also suggested the use of satellite remote sensing technologies as part of official statistical frameworks and methodologies.

Background: Colorectal cancer (CRC) is common and often presents with advanced disease in Africa. Multivisceral resection (MVR) improves survival in locally advanced (T4b) CRC. The aim was to describe the management and outcomes of patients with clinical T4b CRC without metastatic disease who underwent MVR. Methods: A retrospective review of patients with T4 CRC who underwent MVR between January 2008 and December 2013. Results: Four hundred and ninety-four patients were included. Of the 158 with suspected T4 cancer, 44 had MVR, of which one was excluded due to metastases. The mean age was 64 years. The male to female ratio was 1:1. The most commonly resected extra-colorectal structure was the abdominal wall (21%). The median survival was 68 months (SD 13.9). The 5-year disease free (DFS) and overall survival (OS) were 46% and 55%, respectively. Survival of patients with colon and rectum cancer was similar. Intraoperative tumour spillage, vascular/perineural invasion, and anastomotic leakage were independent predictors of survival. Conclusion: Multivisceral resection of locally advanced (T4b) CRC is feasible in the African context. Complete resection improves survival and should be the goal.

In this paper, the accuracy and practical capabilities of three different reduced-order models (ROMs) are explored: an enhanced implicit condensation and expansion (EnICE) model, a finite element beam model, and a finite volume beam model are compared for their capability to accurately predict the nonlinear structural response of geometrically nonlinear built-up wing structures. This work briefly outlines the different order reduction methods, highlighting the associated assumptions and computational effort. The ROMs are then used to calculate the wing deflection for different representative load cases and these results are compared with the global finite element model (GFEM) predictions when possible. Overall, the ROMs are found to be able to capture the nonlinear GFEM behaviour accurately, but differences are noticed at very large displacements and rotations due to local geometrical effects.

Background: Combined multimodal treatment (CMT) is the preferred treatment for anal squamous carcinoma with radical surgery reserved for treatment failure. Some patients require a defunctioning stoma prior to CMT. Successful closure of such a stoma is unlikely. Abdominoperineal excision (APE) may be suitable as primary treatment in these patients. Objectives: To evaluate organ preservation in the treatment of anal squamous cancer and the closure rate of pre-treatment, temporary diverting colostomy, thereby assessing whether APE could be offered as primary treatment in those requiring a pre-treatment colostomy. Methods: A retrospective review of all patients with anal squamous carcinoma was undertaken. Patients who required defunctioning colostomies prior to CMT were analysed for potential resectability of tumour prior to CMT and rate of permanent stoma. Results: One hundred and twenty-five patients were included of which 58 were males. The mean age was 56 years. 107 were treated with curative intent. Six received primary APE and 12 salvage APE. Thirty (22 males) required pretreatment diverting colostomies. Three (10%) stomas were successfully reversed. Forty-eight (38%) of the 125 completed treatment with a permanent colostomy. Six patients who needed a stoma prior to CMT were deemed resectable. Conclusion: Organ preservation was not possible in about a third of patients. Defunctioning stomas prior to CMT were likely to be permanent. We propose that APE could be considered as an alternative in selective cases where the tumour is resectable with low morbidity and a stoma is indicated.

Pseudomonas aeruginosa infection is a major cause of morbidity in burns patients. There is a paucity of publications dealing with this infection in the paediatric population. We describe the incidence, microbiology and impact of P. aeruginosa infection in a dedicated paediatric burns unit. A retrospective review of patients with clinically significant P. aeruginosa infection between April 2007 and January 2010 in the burns unit at Red Cross War Memorial Children's Hospital in Cape Town, South Africa, was performed. During the 36-month study period, 2 632 patients were admitted. Of 2 791 bacteriology samples sent for microscopy, culture and sensitivity, 406 (14.5%) were positive for P. aeruginosa. Thirty-four patients had clinically significant P. aeruginosa wound infection, giving an incidence of 1.3%. Three patients had loss of Biobrane or allografts, and 23 cases of skin graft loss occurred in 18 patients. An average of 12 dressing days was needed to obtain negative swabs. All isolates were sensitive to chlorhexidine, whereas 92.5% were resistant to povidone-iodine. Piperacillin-tazobactam was the systemic antimicrobial to which there was most resistance (36.1%), and tobramycin had least resistance (3.3%). The incidence of clinically significant burn wound infection is low in our unit, yet the morbidity due to debridement and re-grafting is significant. We observed very high resistance to topical povidone-iodine. Resistance to systemic antimicrobials is lower than that reported from other burns units.