155 research outputs found

    On the duration and cost variability of construction activities: an empirical study

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    The unique nature of construction projects can mean that construction activities often suffer from duration and cost variability. As this variability is unplanned it can present a problem when attempting to complete a project on time and on budget. Various factors causing this variability have been identified in the literature, but they predominantly refer to the nature and/or context of the whole project, rather than their specific activities. In this paper, the order of magnitude of and correlation between activity duration and cost variability is analyzed in 101 construction projects with over 5000 activities. To do this, the first four moments (mean, standard deviation, skewness and kurtosis) of actual versus planned duration and cost (log) ratios are analyzed by project, phase of execution and activity type. Results suggest that, contrary to common wisdom, construction activities do not end late on average. Instead, the large variability in the activity duration is the major factor causing significant project delays and cost overruns. The values of average activity duration and cost variability gathered in this study will also serve as a reference for construction managers to improve future construction planning and project simulation studies with more realistic data

    Influence of high cardiovascular risk in asymptomatic people on the duration and cost of sick leave: results of the ICARIA study

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    Aims We investigated the potential influence of a moderate-to-high cardiovascular (CV) risk (CVR) (defined as a Systematic COronary Risk Evaluation model, or SCORE ≥ 4%), in the absence of an established CV disease, on the duration and cost of CV and non-CV sick leave (SL) resulting from common and occupational accidents or diseases. Methods and results We conducted a prospective cohort study on 690 135 workers with a 1-year follow-up and examined CV- and non-CV-related SL episodes. To obtain baseline values, CVR factors were initially assessed at the beginning of the year during routine medical examination. The CVR was calculated with the SCORE charts for all subjects. Moderate-to-high CVR was defined as SCORE ≥ 4%. A baseline SCORE ≥ 4% was associated with a higher risk for long-term CV and non-CV SL, as revealed by follow-up assessment. This translated into an increased cost, estimated at €5 801 464.18 per year. Furthermore, pharmacological treatment for hypertension or hyperlipidaemia was significantly associated with longer SL duration. Conclusion Moderate-to-high CVR in asymptomatic subjects was significantly associated with the duration and cost of CV and non-CV SL. These results constitute the first body of evidence that the SCORE charts can be used to identify people with a non-established CV disease, which might ultimately translate into more lost workdays and therefore increased cost for societ

    Compuestos y reacciones quimicas naturales como motivadores del aprendizaje

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    Uno de los componentes importantes en el proceso de aprendizaje, se relaciona con la fuerte motivación intrínseca que el estudiante muestra hacia los contenidos que debe incorporar. Mas allá de los intereses propios de los alumnos es posible aportar, desde los materiales didácticos con los cuales se trabaja en el aula, información, imágenes, e inquietudes que, al relacionarse con temas aplicados de su entorno natural conduzcan a un aumento en la atención, como modo de mejorar la comprensión, retención y posterior uso activo de los conocimientos adquiridos (Teoría Uno, Perkins, 1995). En esta propuesta el aprendizaje de la escritura de fórmulas y ecuaciones químicas, con todos sus componentes asociados se presenta como material didáctico que describe compuestos y reacciones químicas observables en el entorno natural circundante del alumno

    Compuestos y reacciones quimicas naturales como motivadores del aprendizaje

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    Uno de los componentes importantes en el proceso de aprendizaje, se relaciona con la fuerte motivación intrínseca que el estudiante muestra hacia los contenidos que debe incorporar. Mas allá de los intereses propios de los alumnos es posible aportar, desde los materiales didácticos con los cuales se trabaja en el aula, información, imágenes, e inquietudes que, al relacionarse con temas aplicados de su entorno natural conduzcan a un aumento en la atención, como modo de mejorar la comprensión, retención y posterior uso activo de los conocimientos adquiridos (Teoría Uno, Perkins, 1995). En esta propuesta el aprendizaje de la escritura de fórmulas y ecuaciones químicas, con todos sus componentes asociados se presenta como material didáctico que describe compuestos y reacciones químicas observables en el entorno natural circundante del alumno

    Application of “taxocene surrogation” and “taxonomic sufficiency” concepts to fish farming environmental monitoring. Comparison of BOPA index versus polychaete assemblage structure

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    “Taxocene surrogation” and “taxonomic sufficiency” concepts were applied to the monitoring of soft bottoms macrobenthic assemblages influenced by fish farming following two approaches. Polychaete assemblage evaluation through multivariate analysis and the benthic index BOPA were compared. Six fish farms along the Spanish Mediterranean coast were monitored. Polychaete assemblage provided a suitable picture of the impact gradient, being correlated with total free sulphides. BOPA did not support the impact gradient described by the polychaete assemblage, providing erroneous categorizations. The inclusion of several polychaete families, which were locally identified as indicative of affection to recalculate BOPA, resulted in an improved diagnosis and correlation with the impact gradient. Nevertheless, frequent misclassifications occurred. These results suggest that the structure of polychaete families, sulphides and granulometry conform an appropriate strategy for fish farming monitoring. Biotic indices need to be specifically designed for concrete activities, and regionally validated, because of the environmental plasticity of benthic invertebrates.This research was funded by the Spanish National Plans of Aquaculture (JACUMAR)

    Influence of high cardiovascular risk in asymptomatic people on the duration and cost of sick leave: results of the ICARIA study.

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    AIMS: We investigated the potential influence of a moderate-to-high cardiovascular (CV) risk (CVR) (defined as a Systematic COronary Risk Evaluation model, or SCORE ≥ 4%), in the absence of an established CV disease, on the duration and cost of CV and non-CV sick leave (SL) resulting from common and occupational accidents or diseases. METHODS AND RESULTS: We conducted a prospective cohort study on 690 135 workers with a 1-year follow-up and examined CV- and non-CV-related SL episodes. To obtain baseline values, CVR factors were initially assessed at the beginning of the year during routine medical examination. The CVR was calculated with the SCORE charts for all subjects. Moderate-to-high CVR was defined as SCORE ≥ 4%. A baseline SCORE ≥ 4% was associated with a higher risk for long-term CV and non-CV SL, as revealed by follow-up assessment. This translated into an increased cost, estimated at euro5 801 464.18 per year. Furthermore, pharmacological treatment for hypertension or hyperlipidaemia was significantly associated with longer SL duration. CONCLUSION: Moderate-to-high CVR in asymptomatic subjects was significantly associated with the duration and cost of CV and non-CV SL. These results constitute the first body of evidence that the SCORE charts can be used to identify people with a non-established CV disease, which might ultimately translate into more lost workdays and therefore increased cost for society

    Immune system deregulation in hypertensive patients chronically RAS suppressed developing albuminuria

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    Albuminuria development in hypertensive patients is an indicator of higher cardiovascular (CV) risk and renal damage. Chronic renin-angiotensin system (RAS) suppression facilitates blood pressure control but it does not prevent from albuminuria development. We pursued the identification of protein indicators in urine behind albuminuria development in hypertensive patients under RAS suppression. Urine was collected from 100 patients classified in three groups according to albuminuria development: (a) patients with persistent normoalbuminuria; (b) patients developing de novo albuminuria; (c) patients with maintained albuminuria. Quantitative analysis was performed in a first discovery cohort by isobaric labeling methodology. Alterations of proteins of interest were confirmed by target mass spectrometry analysis in an independent cohort. A total of 2416 proteins and 1223 functional categories (coordinated protein responses) were identified. Immune response, adhesion of immune and blood cells, and phagocytosis were found significantly altered in patients with albuminuria compared to normoalbuminuric individuals. The complement system C3 increases, while Annexin A1, CD44, S100A8 and S100A9 proteins showed significant diminishment in their urinary levels when albuminuria is present. This study reveals specific links between immune response and controlled hypertension in patients who develop albuminuria, pointing to potential protein targets for novel and future therapeutic interventions.Sin financiación4.122 JCR (2017) Q1, 12/64 Multidisciplinary Sciences0.809 SJR (2017) Q2, 4/10 OptometryNo data IDR 2017UE

    Patient-reported outcomes in a phase III, randomized study of sunitinib versus interferon-{alpha} as first-line systemic therapy for patients with metastatic renal cell carcinoma in a European population

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    BACKGROUND: The purpose of this study is to evaluate the impact on the health-related quality of life (HRQoL) of sunitinib versus interferon-alpha (IFN-alpha) treatment in patients with metastatic renal cell carcinoma (mRCC). PATIENTS AND METHODS: In all, 304 mRCC patients (European cohort) were randomized 1 : 1 to receive sunitinib (50 mg/day for 4 weeks, followed by 2 weeks off) or IFN-alpha (9 million units s.c. injection three times/week). The following questionnaires were completed (days 1 and 28 per cycle): Functional Assessment of Cancer Therapy-General (FACT-G), the FACT-Kidney Symptom Index and the EuroQol Group's EQ-5D self-report questionnaire (EQ-5D). Results correspond to an ongoing trial with progression-free survival time as primary end point, and patients were still being followed up. Data were analyzed using repeated measures mixed effects models (MEMs) that allow the inclusion of initial differences and uncompleted repeated measures, with the assumption of data missing at random. Six-cycle results were included. RESULTS: Results consistently showed that patients in sunitinib group experienced statistically significantly milder kidney-related symptoms, better cancer-specific HRQoL and general health status (in social utility scores) during the study period as measured by these patient-reported outcome end points. No statistical differences between groups were found on the FACT-G physical well-being subscale or the EQ-5D VAS values. CONCLUSIONS: Results from MEM showed the sunitinib's benefit on HRQoL compared with IFN-alpha

    The Mitochondrial Genome Is a “Genetic Sanctuary” during the Oncogenic Process

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    Since Otto Warburg linked mitochondrial physiology and oncogenesis in the 1930s, a number of studies have focused on the analysis of the genetic basis for the presence of aerobic glycolysis in cancer cells. However, little or no evidence exists today to indicate that mtDNA mutations are directly responsible for the initiation of tumor onset. Based on a model of gliomagenesis in the mouse, we aimed to explore whether or not mtDNA mutations are associated with the initiation of tumor formation, maintenance and aggressiveness. We reproduced the different molecular events that lead from tumor initiation to progression in the mouse glioma. In human gliomas, most of the genetic alterations that have been previously identified result in the aberrant activation of different signaling pathways and deregulation of the cell cycle. Our data indicates that mitochondrial dysfunction is associated with reactive oxygen species (ROS) generation, leading to increased nuclear DNA (nDNA) mutagenesis, but maintaining the integrity of the mitochondrial genome. In addition, mutational stability has been observed in entire mtDNA of human gliomas; this is in full agreement with the results obtained in the cancer mouse model. We use this model as a paradigm of oncogenic transformation due to the fact that mutations commonly found in gliomas appear to be the most common molecular alterations leading to tumor development in most types of human cancer. Our results indicate that the mtDNA genome is kept by the cell as a “genetic sanctuary” during tumor development in the mouse and humans. This is compatible with the hypothesis that the mtDNA molecule plays an essential role in the control of the cellular adaptive survival response to tumor-induced oxidative stress. The integrity of mtDNA seems to be a necessary element for responding to the increased ROS production associated with the oncogenic process

    Clinical validation of risk scoring systems to predict risk of delayed bleeding after EMR of large colorectal lesions

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    [Background and Aims]: The Endoscopic Resection Group of the Spanish Society of Endoscopy (GSEED-RE) model and the Australian Colonic Endoscopic Resection (ACER) model were proposed to predict delayed bleeding (DB) after EMR of large superficial colorectal lesions, but neither has been validated. We validated and updated these models.[Methods]: A multicenter cohort study was performed in patients with nonpedunculated lesions ≥20 mm removed by EMR. We assessed the discrimination and calibration of the GSEED-RE and ACER models. Difficulty performing EMR was subjectively categorized as low, medium, or high. We created a new model, including factors associated with DB in 3 cohort studies.[Results]: DB occurred in 45 of 1034 EMRs (4.5%); it was associated with proximal location (odds ratio [OR], 2.84; 95% confidence interval [CI], 1.31-6.16), antiplatelet agents (OR, 2.51; 95% CI, .99-6.34) or anticoagulants (OR, 4.54; 95% CI, 2.14-9.63), difficulty of EMR (OR, 3.23; 95% CI, 1.41-7.40), and comorbidity (OR, 2.11; 95% CI, .99-4.47). The GSEED-RE and ACER models did not accurately predict DB. Re-estimation and recalibration yielded acceptable results (GSEED-RE area under the curve [AUC], .64 [95% CI, .54-.74]; ACER AUC, .65 [95% CI, .57-.73]). We used lesion size, proximal location, comorbidity, and antiplatelet or anticoagulant therapy to generate a new model, the GSEED-RE2, which achieved higher AUC values (.69-.73; 95% CI, .59-.80) and exhibited lower susceptibility to changes among datasets.[Conclusions]: The updated GSEED-RE and ACER models achieved acceptable prediction levels of DB. The GSEED-RE2 model may achieve better prediction results and could be used to guide the management of patients after validation by other external groups. (Clinical trial registration number: NCT 03050333.)Research support for this study was received from “La Caixa/Caja Navarra” Foundation (ID 100010434;project PR15/11100006)
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