169 research outputs found

    Perfluorinated alkyl substances (PFASs) in northern Spain municipal solid waste landfill leachates

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    Landfill leachates have been recognized as significant secondary sources of poly- and perfluoroalkyl substances (PFASs). This study presents data on the occurrence and concentration of 11 perfluoroalkyl carboxylates (PFCAs) and 5 perfluoroalkyl sulfonates (PFSAs) in leachates from 4 municipal solid waste landfill sites located across northern Spain. To the best of our knowledge, this is the first report of the presence of PFASs in Spanish landfill leachates. Two of the landfill sites applied on-site treatment using membrane bioreactors (MBR), and its effect on PFASs occurrence is also reported. Total PFASs (∑PFASs) in raw leachates reached 1378.9 ng/L, while in treated samples ∑PFASs was approximately two-fold (3162.3 ng/L). PFCAs accounted for the majority of the detected PFASs and perfluorooctanoic acid (PFOA) was the dominant compound in raw leachates (42.6%), followed by shorter chain PFHxA (30.1%), PFPeA and PFBA. The age of the sites might explain the PFASs pattern found in raw leachates as all of them were stabilized leachates. However, PFASs profile was different in treated samples where the most abundant compound was PFHxA (26.5%), followed by linear perfluorobutane sulfonate (L-PFBS) (18.7%) and PFOA (17.7%). The overall increase of the PFASs content as well as the change in the PFASs profile after the MBR treatment, could be explained by the possible degradation of PFASs precursors such as fluorotelomer alcohols or fluorotelomer sulfonates. Using the volume of leachates generated in the landfill sites, that served 1.8 million people, the discharge of 16 ∑PFASs contained in the landfill leachates was estimated as 1209 g/year.The authors thank financial support from the Spanish Ministry of Economy and Competitiveness (Project CTM2013-44081-R)

    Compiling SHIM

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    Embedded systems demand concurrency for supporting simultaneous actions in their environment and parallel hardware. Although most concurrent programming formalisms are prone to races and non-determinism, some, such as our SHIM (software/hardware integration medium) language, avoid them by design. In particular, the behavior of SHIM programs is scheduling-independent, meaning the I/O behavior of a program is independent of scheduling policies, including the relative execution rates of concurrent processes. The SHIM project demonstrates how a scheduling-independent language simplifies the design, optimization, and verification of concurrent systems. Through examples and discussion, we describe the SHIM language and code generation techniques for both shared-memory and message-passing architectures, along with some verification algorithms

    Differences in access to coronary care unit among patients with acute myocardial infarction in Rome: old, ill, and poor people hold the burden of inefficiency

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    BACKGROUND: Direct admission to Coronary Care Unit (CCU) on hospital arrival can be considered as a good proxy for adequate management in patients with acute myocardial infarction (AMI), as it has been associated with better prognosis. We analyzed a cohort of patients with AMI hospitalized in Rome (Italy) in 1997–2000 to assess the proportion directly admitted to CCU and to investigate the effect of patient characteristics such as gender, age, illness severity on admission, and socio-economic status (SES) on CCU admission practices. METHODS: Using discharge data, we analyzed a cohort of 9127 AMI patients. Illness severity on admission was determined using the Deyo's adaptation of the Charlson's comorbidity index, and each patient was assigned to one to four SES groups (level I referring to the highest SES) defined by a socioeconomic index, derived by the characteristics of the census tract of residence. The effect of gender, age, illness severity and SES, on risk of non-admission to CCU was investigated using a logistic regression model (OR, CI 95%). RESULTS: Only 53.9% of patients were directly admitted to CCU, and access to optimal care was more frequently offered to younger patients (OR = 0.35; 95%CI = 0.25–0.48 when comparing 85+ to >=50 years), those with less severe illness (OR = 0.48; 95%CI = 0.37–0.61 when comparing Charlson index 3+ to 0) and the socially advantaged (OR = 0.81; 95%CI = 0.66–0.99 when comparing low to high SES). CONCLUSION: In Rome, Italy, standard optimal coronary care is underprovided. It seems to be granted preferentially to the better off, even after controversial clinical criteria, such as age and severity of illness, are taken into account

    A critical review of mathematical models and data used in diabetology

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    The literature dealing with mathematical modelling for diabetes is abundant. During the last decades, a variety of models have been devoted to different aspects of diabetes, including glucose and insulin dynamics, management and complications prevention, cost and cost-effectiveness of strategies and epidemiology of diabetes in general. Several reviews are published regularly on mathematical models used for specific aspects of diabetes. In the present paper we propose a global overview of mathematical models dealing with many aspects of diabetes and using various tools. The review includes, side by side, models which are simple and/or comprehensive; deterministic and/or stochastic; continuous and/or discrete; using ordinary differential equations, partial differential equations, optimal control theory, integral equations, matrix analysis and computer algorithms

    Finding Common Ground When Experts Disagree: Robust Portfolio Decision Analysis

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    Influence of different types of solvent on the effectiveness of nanolime treatments on highly porous mortar substrates

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    Historic calcareous structures suffer from weathering processes that result in the loss of some of their original properties. Nanolime products represent an attractive choice for the consolidation of these substrates containing calcite due to their high chemical compatibility with the original structure. The effectiveness of nanolime products has been widely proven for superficial consolidation treatments (e.g. plasters and wall-paintings). However, its consolidation mechanism in highly porous substrates (e.g. limestones or lime mortars) still needs to be fully understood. The aim of this paper is to study the influence of different types of solvent on the effectiveness of nanolime treatments on highly porous lime-mortars. The consolidation effectiveness is investigated by evaluating changes on superficial cohesion, porosity, drilling resistance, water absorption by capillarity, drying rate and aesthetic properties. Results showed that nanolime dispersed in a mixture of isopropanol (50%) and water (50%) yielded slightly better consolidation properties in terms of reduction in porosity, increase in strength and penetration within coarse lime-mortars than nanolime dispersed in other solvents

    The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

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    Background: Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy. Methods: Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored. Results: A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays. Conclusions: IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients

    'Miss, you're so gay.' Queer stories from trainee teachers

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    This is a postprint of an article whose final and definitive form has been published in Sex Education© 2004 Copyright Taylor & Francis; Sex Education is available online at http://www.informaworld.comThis study focuses on interviews with six lesbian, gay or bisexual trainee teachers, and explores their experiences in relation to sexual orientation. Initial analysis reveals interesting perspectives on the lives of trainees in Higher Education, during school-based work and socially; it also provides a window onto the attitudes to sexuality (individual and institutional) encountered by interviewees. Further analysis takes theoretical tools from three overlapping discourses in which these trainees are participants: the local campus culture, the construction of sexualities in schools, and wider society's perceptions of gender and sexuality. These tools uncover significant concerns around identity management, vulnerability and powerlessness, institutional silence, and the hegemonic masculinity of some student cultures. They also reveal significant creative resistance to discrimination, enabling us to conclude that, in spite of some methodological difficulties, idealism is not misplaced as an inspiration to emancipatory endeavour
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