The Multimode Resource Constrained Project Scheduling Problem for Repetitive Activities in Construction Projects

[EN] In construction projects, resource availability might limit the implementation of ideal schedules. Especially, when repetitive activities are involved, traditional resource¿constrained project scheduling problem (RCPSP) models fail to allocate the resource consumption in an efficient manner. Besides, actual models only provide local optimal solutions and do not incorporate activity acceleration routines. To fulfill this gap, partially, a mathematical optimization model, the multimode RCPSP for repetitive activities in construction projects, is proposed and solved to optimality; it takes into account acceleration routines under real construction scenarios using spreadsheets. The article shows a complete computational experimentation over a real construction project, considering several scenarios of resource availabilities and continuity conditions. The model allows analyzing the resources efficiency indexes comparing them to resource consumptions, continuity of activities, and objective functions that reveal that fragmented activities do not provide better resource efficiency outcomes.This research was partially supported by the FAPA program of Universidad de Los Andes, Colombia (code P14.246922.005/01). The authors would also like to thank the research group of Construction Engineering and Management (INgeco) at Universidad de los Andes.García-Nieves, J.; Ponz-Tienda, JL.; Salcedo-Bernal, A.; Pellicer Armiñana, E. (2018). The Multimode Resource Constrained Project Scheduling Problem for Repetitive Activities in Construction Projects. Computer-Aided Civil and Infrastructure Engineering. 33(8):655-671. https://doi.org/10.1111/mice.12356S65567133

Management of cerebral venous thrombosis in Spain : MOTIVATE descriptive study Manejo de la trombosis venosa cerebral en España: estudio descriptivo MOTIVATE

Introduction: Cerebral venous thrombosis (CVT) is an uncommon cause of stroke that mainly affects young adults. Early, accurate diagnosis can reduce the rate and severity of complications. Objective: The aim of this study was to analyse the clinical characteristics, management, and treatment of CVT in different centres in Spain. Methods: We conducted a multicentre, retrospective, descriptive study of patients hospitalised due to CVT between 2008 and 2017 at 11 Spanish centres. Results: We included 256 patients, with a mean age (SD) of 49.8 (18.7) years; 51% of patients were women. The most frequent symptoms were headache (73%), focal deficits (50%), epileptic seizures (33%), and encephalopathy (21%). The most frequent localisations were the superior sagittal sinus (12.5%), the transverse sinus (10.9%), and 2 or more sinuses or veins (66.4%). Thrombophilia was the most frequent known aetiology (24%), and was most commonly associated with the prothrombin G20210A mutation (19%). Forty-six percent of patients were treated with antithrombotics for 3-6 months, 21% for one year, and 22.6% required indefinite anticoagulation. Endovascular therapy was performed in 5% of cases, and 33% required neurosurgery. Regarding outcomes, 75% of patients were independent at 3 months (modified Rankin Scale [mRS] score ≤ 2), with papilloedema (P =.03), focal deficits (P =.001), and encephalopathy (P 3). The in-hospital mortality rate was 4.3%, with a 3-month mortality rate of 6.3%. Conclusion: The diverse risk factors and variable presentation of CVT represent a challenge in the diagnosis and treatment of this condition. To improve prognosis and reduce mortality, it is essential to establish management protocols for this entity

Colorectal cancer, one entity or three*

Understanding of the mechanism of colorectal carcinogenesis has been gaining momentum for some years on account of its high incidence and impact on the lives of individuals affected. Different genetic abnormalities have been found in colorectal cancers from different sites. For example, proximal colon cancer is usually related to the nucleotide instability pathway, as microsatellite instability (MSI). However, distal colon cancer is usually associated with specific chromosomal instability (CIN). The development of cancer at the rectum, though similar to that at the colon, displays its own unique features. These differences might be partially attributed to different embryological development and physiological circumstances. Environmental factors such as diet and alcohol intake also differ in their role in the development of tumors in the three segments, proximal colon, distal colon, and rectum. “Proximal shift” of colon cancer has been known for some time, and survival rates of colorectal cancer are higher when rectal cancers are excluded, both of which emphasize the three different segments of colorectal cancer and their different properties. Meanwhile, colonic and rectal cancers are distinctive therapeutic entities. The concept of three entities of colorectal cancer may be important in designing clinical trails or therapeutic strategies. However, the dispute about the inconsistency of data concerning the site-specific mechanism of colorectal carcinoma does exist, and more evidence about molecular events of carcinogenesis and targeted therapy needs to be collected to definitely confirm the conception