Risk assessment for reservoir development under uncertainty

Decision analysis applied to petroleum field development is always strongly related to risk due to the uncertainties present in the process. Methodologies to quantify the impact of uncertainties are still not well established due to the amount of variables that have to be considered. The complete analysis usually depends on geological, economical and technological uncertainties that have different degrees of impact in the recovery process and may affect the decision process at different levels depending on the problem, reservoir characteristics, recovery mechanism and stage of field development. This paper shows several details of a methodology that can be applied to complex and simple reservoirs in a reasonable amount of time, discussing especially the influence of the model used to predict recovery, choice of production strategies to be used in the process, number of attributes and type of information necessary to obtain reliable results. A discussion of data integration among geology, reservoir engineering and economic analysis also is presented in order to reduce the amount of information necessary and time for the process. Some results are presented to show the advantages of automation and parallel computing to reduce the total time of the procedure where reservoir simulation is necessary for reservoir performance prediction.21321

Organic and conventional dairy goat production systems in Andalusian mountainous areas

Organic goat production is poorly developed in Spain. Conventional dairy goat production systems located in Andalusian mountainous areas greatly depend on pasturing which implies that its transformation to organic model is not difficult. The objective of this paper is to evaluate the viability of organic dairy goat farms –as compared to conventional–, and to study the possibilities of transitioning from conventional to organic goat production. This study was carried out in 2006 in Sierra de Cádiz (Andalusia) with the autochthonous breed Payoya. To monitor technico-economic aspects of goat farms, FAO-CIHEAM method was implemented. Results indicate that organic farms are economically viable, due mainly to low costs of external feeds and income from European Union subsidies. For transitioning from conventional to organic dairy goat production a reduction of consumption of concentrates per animal and per year and/or cultivate grain on the farm are necessary.La production caprine biologique est encore peu développée en Espagne. Les systèmes caprins laitiers dans les zones de montagne de l’Andalousie disposent de grandes surfaces pour le pâturage, et, par conséquent, il est assez facile de transformer ces systèmes en systèmes biologiques. L’objectif de ce travail est d’évaluer la viabilité des systèmes caprins biologiques par rapport aux systèmes caprins conventionnels et d’étudier les possibilités de conversion des systèmes conventionnels en systèmes biologiques. L’étude a été réalisée en 2006 dans la Sierra de Cádiz (Andalousie) avec une race autochtone (Payoya). On a utilisé la méthodologie FAO-CIHEAM pour le suivi technico-économique des exploitations caprines. Les résultats montrent que les systèmes biologiques sont économiquement viables compte tenu surtout des moindres coûts alimentaires par rapport aux systèmes conventionnels et des aides de l’Union Européenne. Pour réussir la transformation des systèmes laitiers caprins conventionnels en systèmes biologiques, il faut réduire l’apport de concentrés et essayer de les produire dans l’exploitation.Junta Andalucí

Prevalence, clinical characteristics and outcome of severe primary HIV-1 infection: a prospective cohort study

Background: Severe cases of primary HIV infection have been described in patients presenting with neurological involvement, AIDS defining events or other life-threatening events. These severe forms have not been fully studied. Objectives: To determine the prevalence and characteristics of severe PHI in a hospital-based cohort of primary HIV infection, and the response to the early initiation of antiretroviral therapy (ART) at 12 months. Methods: Every patient with PHI attending Hospital Clínic of Barcelona (1997-2015) was evaluated. Severe PHI was defined using clinical, analytical and immunological criteria. Chi-squared test was used for categorical variables and Student's t-test for quantitative variables. Results: 33% of 224 PHI patients (95% CI: 26.84%-39.16%) had a severe PHI. These patients had more symptoms, abnormal analytical parameters and hospital admissions. The severe PHI group had a significantly higher viral load although no differences were observed at 12 months in terms of viral suppression or CD4 count recovery. None died during PHI. Conclusions: Up to one third of patients in our cohort presented with a severe PHI, which was associated with higher hospitalization rates and higher plasma HIV RNA viral load. However, severe forms were not associated to a worse clinical, immunological or virological outcome at 12 months

A Model for the Development of the Rhizobial and Arbuscular Mycorrhizal Symbioses in Legumes and Its Use to Understand the Roles of Ethylene in the Establishment of these two Symbioses

We propose a model depicting the development of nodulation and arbuscular mycorrhizae. Both processes are dissected into many steps, using Pisum sativum L. nodulation mutants as a guideline. For nodulation, we distinguish two main developmental programs, one epidermal and one cortical. Whereas Nod factors alone affect the cortical program, bacteria are required to trigger the epidermal events. We propose that the two programs of the rhizobial symbiosis evolved separately and that, over time, they came to function together. The distinction between these two programs does not exist for arbuscular mycorrhizae development despite events occurring in both root tissues. Mutations that affect both symbioses are restricted to the epidermal program. We propose here sites of action and potential roles for ethylene during the formation of the two symbioses with a specific hypothesis for nodule organogenesis. Assuming the epidermis does not make ethylene, the microsymbionts probably first encounter a regulatory level of ethylene at the epidermis–outermost cortical cell layer interface. Depending on the hormone concentrations there, infection will either progress or be blocked. In the former case, ethylene affects the cortex cytoskeleton, allowing reorganization that facilitates infection; in the latter case, ethylene acts on several enzymes that interfere with infection thread growth, causing it to abort. Throughout this review, the difficulty of generalizing the roles of ethylene is emphasized and numerous examples are given to demonstrate the diversity that exists in plants

Management of MDR-TB in HIV co-infected patients in Eastern Europe: Results from the TB: HIV study

Objectives: Mortality among HIV patients with tuberculosis (TB) remains high in Eastern Europe (EE), but details of TB and HIV management remain scarce. Methods: In this prospective study, we describe the TB treatment regimens of patients with multi-drug resistant (MDR) TB and use of antiretroviral therapy (ART). Results: A total of 105 HIV-positive patients had MDR-TB (including 33 with extensive drug resistance) and 130 pan-susceptible TB. Adequate initial TB treatment was provided for 8% of patients with MDR-TB compared with 80% of those with pan-susceptible TB. By twelve months, an estimated 57.3% (95%CI 41.5-74.1) of MDR-TB patients had started adequate treatment. While 67% received ART, HIV-RNA suppression was demonstrated in only 23%. Conclusions: Our results show that internationally recommended MDR-TB treatment regimens were infrequently used and that ART use and viral suppression was well below the target of 90%, reflecting the challenging patient population and the environment in which health care is provided. Urgent improvement of management of patients with TB/HIV in EE, in particular for those with MDR-TB, is needed and includes widespread access to rapid TB diagnostics, better access to and use of second-line TB drugs, timely ART initiation with viral load monitoring, and integration of TB/HIV care

Multicentre International Registry of Open Surgical Versus Percutaneous Upper Extremity Access During Endovascular Aortic Procedures

Objective: To investigate access failure (AF) and stroke rates of aortic procedures performed with upper extremity access (UEA), and compare results of open surgical vs. percutaneous UEA techniques with closure devices. Methods: A physician initiated, multicentre, ambispective, observational registry (SUPERAXA - NCT04589962) was carried out of patients undergoing aortic procedures requiring UEA, including transcatheter aortic valve replacement, aortic arch, and thoraco-abdominal aortic endovascular repair, pararenal parallel grafts, renovisceral and iliac vessel repair. Only vascular procedures performed with an open surgical or percutaneous (with a suture mediated vessel closure device) UEA were analysed. Risk factors and endpoints were classified according to the Society for Vascular Surgery and VARC-3 (Valve Academic Research Consortium) reporting standards. A logistic regression model was used to identify AF and stroke risk predictors, and propensity matching was employed to compare the UEA closure techniques. Results: Sixteen centres registered 1 098 patients (806 men [73.4%]; median age 74 years, interquartile range 69 – 79 years) undergoing vascular procedures using open surgical (76%) or percutaneous (24%) UEA. Overall AF and stroke rates were 6.8% and 3.0%, respectively. Independent predictors of AF by multivariable analysis included pacemaker ipsilateral to the access (odds ratio [OR] 3.8, 95% confidence interval [CI] 1.2 – 12.1; p =.026), branched and fenestrated procedure (OR 3.4, 95% CI 1.2 – 9.6; p =.019) and introducer internal diameter ≥ 14 F (OR 6.6, 95% CI 2.1 – 20.7; p =.001). Stroke was associated with female sex (OR 3.4, 95% CI 1.3 – 9.0; p =.013), vessel diameter > 7 mm (OR 3.9, 95% CI 1.1 – 13.8; p =.037), and aortic arch procedure (OR 7.3, 95% CI 1.7 – 31.1; p =.007). After 1:1 propensity matching, there was no difference between open surgical and percutaneous cohorts. However, a statistically significantly higher number of adjunctive endovascular procedures was recorded in the percutaneous cohort (p <.001). Conclusion: AF and stroke rates during complex aortic procedures employing UEA are non-negligible. Therefore, selective use of UEA is warranted. Percutaneous access with vessel closure devices is associated with similar complication rates, but more adjunctive endovascular procedures are required to avoid surgical exposure

H∞ filtering for non-linear systems with stochastic sensor saturations and Markov time delays: The asymptotic stability in probability

This study is concerned with the filtering problem for a class of non-linear systems with stochastic sensor saturations and Markovian measurement transmission delays, where the asymptotic stability in probability is considered. The sensors are subject to random saturations characterised by a Bernoulli distributed sequence. The transmission time delays are governed by a discrete-time Markov chain with finite states. In the presence of the non-linearities, stochastic sensor saturations and Markovian time delays, sufficient conditions are established to guarantee that the filtering process is asymptotically stable in probability without disturbances and also satisfies the H∞ criterion with respect to non-zero exogenous disturbances under the zero-initial condition. Moreover, it is illustrated that the results can be specialised to linear filters. Two simulation examples are presented to show the effectiveness of the proposed algorithms.This work was supported by National Natural Science Foundation of China under Grants 61490701, 61290324, 61273156, 61473163, and 61210012, and Research Fund for the Taishan Scholar Project of Shandong Province of China, and Jiangsu Provincial Key Laboratory of E-business at Nanjing University of Finance and Economics of China under Grant JSEB201301, and Tsinghua University Initiative Scientific Research Program

Barriers to health care services for migrants living with HIV in Spain

BACKGROUND: In Spain, migrants are disproportionately affected by HIV and experience high rates of late diagnosis. We investigated barriers to health care access among migrants living with HIV (MLWH) in Spain. METHODS: Cross sectional electronic survey of 765 adult HIV-positive migrants recruited within 18 health care settings between July 2013 and July 2015. We collected epidemiological, demographic, behavioral and clinical data. We estimated the prevalence and risk factors of self-reported barriers to health care using multivariable logistic regression. RESULTS: Of those surveyed, 672 (88%) had information on health care access barriers: 23% were women, 63% from Latin America and Caribbean, 14% from Sub-Saharan Africa and 15% had an irregular immigration status. Men were more likely to report barriers than women (24% vs. 14%, P = 0.009). The main barriers were: lengthy waiting times for an appointment (9%) or in the clinic (7%) and lack of a health card (7%). Having an irregular immigration status was a risk factor for experiencing barriers for both men (OR: (4.0 [95%CI: 2.2–7.2]) and women (OR: 10.5 [95%CI: 3.1–34.8]). Men who experienced racial stigma (OR: 3.1 [95%CI: 1.9–5.1]) or food insecurity (OR: 2.1 [95%CI: 1.2–3.4]) were more likely to report barriers. Women who delayed treatment due to medication costs (6.3 [95%CI: 1.3–30.8]) or had a university degree (OR: 5.8 [95%CI: 1.3–25.1]) were more likely to report barriers. CONCLUSION: Health care barriers were present in one in five5 MLWH, were more common in men and were associated to legal entitlement to access care, perceived stigma and financial constraints