Calculating fault propagation in functional programs

Techn. Report TR-HASLab:01:2013The production of safety critical software is bound to a number of safety and certification standards in which estimating the risk of failure plays a central role. Yet risk estimation seems to live outside most programmers’ core practice, involving simulation techniques and worst case analysis performed a posteriori. In this paper we propose that risk be constructively handled in functional programming by writing programs which choose between expected and faulty be- haviour and by reasoning about them in a linear algebra extension to the standard algebra of programming. In particular, the paper calculates propagation of faults across standard program transformation techniques known as tupling and fusion, enabling the fault of the whole to be expressed in terms of the faults of its parts.Fundação para a Ciência e a Tecnologia (FCT

Sludge removal enterprises in Indonesia: Factors affecting entrepreneurial success

© IWA Publishing 2018. Faecal sludge removal is critical for the long-term functionality of on-site sanitation facilities and sustained sanitation outcomes. Private enterprises are important players in providing sludge removal services in Indonesia and other countries where government does not do so. However, the extent to which sludge removal entrepreneurs can fulfil this role depends on the viability, or success, of their enterprises. This paper investigates factors linked to the success of sludge removal enterprises in Indonesia, including traits of the entrepreneurs, characteristics of the enterprises and contextual challenges. These factors and levels of success were examined from data collected from structured interviews with 24 sludge removal enterprises across six cities in Indonesia. This research found that higher levels of success were significantly associated with entrepreneurs that had previous work experience of any kind, made higher upfront investments and did not involve their family members in the management of the enterprise. Participants most frequently identified high costs of capital, high levels of competition and insufficient time to spend on the enterprise as challenges to success. These findings provide important evidence for how civil society organisations and governments in Indonesia and elsewhere may best provide a conducive enabling environment for enterprise roles in sludge removal

Aging effect on the integrity of traditional Portuguese timber roof structures

Traditional buildings basically include natural and autochthonous construction materials and are built with sustainable construction techniques. The knowledge of these materials’s state and construction techniques is required for a proper conservation/renovation work. It is well known that the lack of maintenance is one of the main causes that contribute to the high degree of degradation that the Portuguese traditional buildings unfortunately have. That degradation may even compromise the overall structural integrity of the building thus reducing its lifetime`s expectation. Meanwhile, a partial or even full demolition of a building is still an often occurrence in the Portuguese context. From a sustainable and building heritage perspectives that practise may be inadequate. Taking into account that generally the degradation problems are linked with roof`s leaking anomalies and that the structural components of the roof tend to be the first ones to be affected, this timber structural roof components of Portuguese dwellings were the object of the research work here presented

Sanitation value chains in low density settings in Indonesia and Vietnam: Impetus for a rethink to achieve pro-poor outcomes

© 2017 The Authors. This study examined the sanitation hardware supply chain in rural, low density settings in Indonesia and Vietnam. Actual costs along the chains were investigated to understand the challenges and opportunities to support affordable sanitation in remote, rural locations. Data were collected from four remote districts in Indonesia and Vietnam through a systematic value-chain analysis comprising 378 interviews across households and supply chain actors and both quantitative and qualitative analysis. Three main findings are presented. Firstly, poor households, often located in remote areas and with lower sanitation access, often experienced higher costs to build durable latrines than households in accessible areas or district capitals. Second, locally sourced materials (sand, bricks or gravel) had a greater influence on price than externally sourced materials (cement, steel and toilet pans), even accounting for cost increases of these materials along the supply chain. Thirdly, transport and labour costs represented considerable proportions of the overall cost to build a toilet. These findings highlighted logistical and financial barriers to poor, remote households in accessing sanitation. Findings can inform strategies to improve the availability and affordability of sanitation products and services, in particular key issues that need to be addressed through government and non-government pro-poor market-based interventions

Avaliação do Desempenho do Teste de Rastreio de Alergia Alimentar FP5® (DPC-Amerlab)

Introdução: A utilização dos testes de rastreio para detecção de IgE específica sérica para diversos alergénios tem sido discutida, sendo invariavelmente aceite a sua utilidade no que diz respeito aos aeroalergénios, não tendo sido ainda suficientemente estabelecida a eficiência dos testes correspondentes destinados à detecção de alergénios alimentares, como acontece com o FP5® da Diagnostic Products Corporation (contendo mistura de clara de ovo, leite, bacalhau, trigo,soja e amendoim). Objectivo: Avaliar o desempenho do teste FP5®, determinando a sua sensibilidade, especificidade e comparação com os métodos de detecção das correspondentes IgE específicas isoladas. Material e métodos: Foi incluída uma amostra aleatória de 54 soros de crianças com alergia alimentar e com determinações de IgE específica positivas para um ou mais dos alimentos testados pelo FP5® - grupo de estudo; foi seleccionado um grupo controlo de 27 amostras de sangue de crianças sem alergia alimentar e em que a determinação de IgE específica para todos os alimentos incluídos no painel em estudo foi negativa. Em ambos os grupos foi efectuada determinação da concentração de IgE específica sérica (kU/l) para FP5®, F1 (clara de ovo), F2 (leite), F3 (bacalhau), F4 (trigo), F13 (soja) e F14 (amendoim), pelo método de quimioluminiscência Immulite®2000. O valor de cut-off considerado foi de 0,35 kU/l. Resultados: Foram testados 81 soros encontrando-se os seguintes parâmetros do teste: sensibilidade=88,9%, especificidade =100%, valor predictivo positivo=100%, valor predictivo negativo=81,8%,eficiência=92,6%. Considerando cada uma das IgE específicas do painel, verificou-se que em todos os soros com determinações positivas para F3, F4, F13 e F14, o FP5® foi também positivo; no caso dos alergénios F1 e F2, observaram-se 3 resultados discrepantes para cada (falsos-negativos). Correlacionando os resultados do FP5® (quantitativos) e o somatório das correspondentes IgE específicas, obtivemos um coeficiente de 0.99, p<0.001. Conclusões: De acordo com os resultados obtidos, verifica-se que o teste de rastreio estudado apresenta boa sensibilidade e eficiência, eexcelente especificidade. De salientar ainda que se trata de um teste que envolve significativa rentabilização de recursos económicos, quando comparado com a determinação das correspondentes IgE específicas isoladas. Concluímos tratar-se de um método cuja utilidade poderá ser considerada na abordagem inicial do doente com suspeita de alergia alimentar IgE mediada, no âmbito dos cuidados de saúde primários

Analysis of the Clinicopathological Characteristics of Patients with Upper Urinary Tract Transitional Cell Carcinoma

OBJECTIVE: To describe the clinicopathological characteristics of patients with upper urinary tract transitional cell carcinomas who are treated surgically and to analyze the occurrence of bladder tumors as well as the development of metastases outside the urinary tract. MATERIALS AND METHODS: The study comprised a retrospective analysis of 25 patients treated between February 1994 and August 2006. The variables analyzed were: patient age, gender, and clinical presentation; diagnostic methods; pathologic characteristics at the primary site of the tumor (pelvis or ureter); tumor stage and grade; and presence of carcinoma in situ, microvascular invasion and squamous differentiation. The Kaplan-Meier method and the Log-Rank test were used for statistical analysis of bladder recurrence-free survival. RESULTS: Eighty-four percent of patients were male, and macroscopic hematuria was the most common clinical presentation. The majority of cases (56%) were infiltrative (T2-T3) and high-grade (76%) tumors. Synchronous or metachronous bladder tumors were found in 72% of cases. Five (20%) patients had a history of bladder tumor before the diagnosis of upper urinary tract transitional cell carcinomas. The mean follow-up period was 36 months (range: 1.5 to 156). During the follow-up period, eleven (44%) patients developed bladder tumors. After five years, the probability of being free of bladder tumor recurrence was 40%. No pathological variable was predictive for bladder tumor recurrence. Four patients presented disease recurrence outside the urinary tract. CONCLUSIONS: The presence of metachronous bladder tumors is more often observed after the diagnosis of upper urinary tract transitional cell carcinomas. All of these patients should undergo rigorous follow-up during the postoperative period. Only patients with infiltrative and high-grade tumors developed metastases outside the urinary tract