Locating waste pipelines to minimize their impact on marine environment

A waste pipeline, considered as an undesirable facility, is to be located in a coastal region. Two criteria are taken into account, the Euclidean distance from a given set of protected areas (coral reefs and sandbanks) and a utility function related to the pipe length, both to be maximized. The paper describes a methodology to obtain an efficient set of points where the extreme of a marine pipeline should be located. Since the formulation of the model is based on the zone Voronoi diagram, the computational complexity of the solving procedure is low

The path-variance problem on tree networks

Extensive facility location models on graphs deal with the location of a special type of subgraphs such as paths, trees or cycles and can be considered as extensions of classical point location models. Variance is one of the measures applied in models in which some equality requirement is imposed. In this paper the problem of locating a minimum variance path in a tree network is addressed, and an O(n2 log n) time algorithm is proposed.Ministerio de Ciencia y Tecnología BFM2000-1052-C02-0

Philadelphia-negative chronic myeloproliferative neoplasm follow-up: when the phone rings. Changes during the COVID-19 pandemic and patient satisfaction. Experience in 30 health centers in Spain.

The SARS-CoV-2 pandemic has favored the expansion of telemedicine. Philadelphia-negative chronic myeloproliferative neoplasms (Ph-MPN) might be good candidates for virtual follow-up. In this study, we aimed to analyze the follow-up of patients with Ph-MPN in Spain during COVID-19, its effectiveness, and acceptance among patients. We present a multicenter retrospective study from 30 centers. Five hundred forty-one patients were included with a median age of 67 years (yr). With a median follow-up of 19 months, 4410 appointments were recorded. The median of visits per patient was 7 and median periodicity was 2.7 months; significantly more visits and a higher frequency of them were registered in myelofibrosis (MF) patients. 60.1% of visits were in-person, 39.5% were by telephone, and 0.3% were videocall visits, with a predominance of telephone visits for essential thrombocythemia (ET) and polycythemia vera (PV) patients over MF, as well as for younger patients