Train schedule optimization for commuter-metro networks

The interconnection and synchronization among different transport modes have been more and more attractive as the modern transportation system is moving towards Mobility-as-a Service. In this study, we address the train scheduling problem for "commuter rail-metro"systems, where the trains from commuter rail lines can go directly into metro systems to provide seamless services for passengers. To optimize the schedule of trains for both commuter rail lines and metro lines, we propose a job shop scheduling model where precedence constraints from commuter-metro networks are taken into account and develop a mixed-integer programming (MIP) model with quadratic constraints. Our model considers the orders of different types of trains and the safety constraints, due to different types of signalling equipment in commuter and metro systems. Since these constraints involve a set of IF-THEN rules, we prove that these constraints can be equivalently reformulated as linear inequalities, without adding new variables. To solve the proposed model efficiently, we design an iterative solution framework, which generates a feasible solution using dynamic programming, next solves a MIP model, then calculates the train speed profiles, and if train speed profiles violate the safety constraints, re optimizes the MIP model with modified alternative constraints. To verify the effectiveness of the proposed approaches, numerical experiments are performed on small and real-world instances based on the Beijing metro Line 1 and the Batong Line operational data

Scheduling of Coupled Train Platoons for Metro Networks: A Passenger Demand-Oriented Approach

In recent years the concept of virtual coupling, where multiple train units are virtually coupled into a platoon with very short following distances, has received considerable attention in the railway transportation field. This study introduces this concept into the train scheduling problem to improve line capacity and reduce congestion in urban metro networks. With consideration of the time-dependent passenger demand, train (platoon) loading capacity, and limited rolling stock resources, specifically, a mixed integer linear programming model is developed to simultaneously generate the platoon (de)coupling strategies, orders of trains, and their arrival/departure times at each station in the metro network. Several model improvement strategies, for example, model linearization and determination of big- M values, are proposed to enhance the computational efficiency of the model. Finally, numerical experiments based on historical passenger data from the Beijing metro network are implemented to verify the effectiveness of the approach. The results demonstrate that the introduction of train platoons of different sizes can evidently reduce station congestion, while the percentage improvement greatly depends on the distribution of passenger demand

Transition in endocrinology: predictors of drop-out of a heterogeneous population on a long-term follow-up

Purpose To evaluate: (1) clinical and epidemiological characteristics of outpatients transitioned from Pediatrics Endocrine (PED) to Adult Endocrine Department (AED) in a tertiary center; (2) transition process features, and predictors of drop-out.Methods Demographic, clinical, and transition features of 170 consecutive patients with pediatric onset of chronic endocrine or metabolic disease (excluded type 1 diabetes) who transitioned from PED to AED (2007-2020) were retrospective evaluated.Results The age at transition was 18.4 +/- 4 years (F:M = 1.2: 1), and mean follow-up 2.8 years. The population was heterogeneous; the most (69.4%) was affected by one, 24.1% by two or more endocrine diseases, 6.5% were followed as part of a cancer survivor's surveillance protocol. The comorbidity burden was high (37, 20.6, and 11.2% of patients had 2, 3, 4, or more diseases). The number of visits was associated with the number of endocrine diseases and the type of them. Adherent subjects had a higher number of comorbidities. Thyroid disorders and more than one comorbidity predicted the adherence to follow-up. Having performed one visit only was predictive of drop-out, regardless of the pathology at diagnosis.Conclusion This is the first study that analyzed a specific transition plan for chronic endocrine diseases on long-term follow-up. The proposed "one-size-fits-all model " is inadequate in responding to the needs of patients. A structured transition plan is an emerging cornerstone

Gestational Diabetes Mellitus: Clinical Characteristics and Perinatal Outcomes in a Multiethnic Population of North Italy

Aim: To evaluate clinical characteristics and perinatal outcomes in a heterogeneous population of Caucasians born in Italy and High Migration Pressure Countries (HMPC) women with GDM living in Piedmont, North Italy. Methods: We retrospectively analyzed data from 586 women referring to our unit (2015-2020). Epidemiological (age and country of origin) and clinical-metabolic features (height, weight, family history of DM, parity, previous history of GDM, OGTT results, and GDM treatment) were collected. The database of certificates of care at delivery was consulted in relation to neonatal/maternal complications (rates of caesarean sections, APGAR score, fetal malformations, and neonatal anthropometry). Results: 43.2% of women came from HMPC; they were younger (p < 0.0001) and required insulin treatment more frequently than Caucasian women born in Italy (χ 2 = 17.8, p=0.007). Higher fasting and 120-minute OGTT levels and gestational BMI increased the risk of insulin treatment (OGTT T0: OR = 1.04, CI 95% 1.016-1.060, p=0.005; OGTT T120: OR = 1.01, CI 95% 1.002-1.020, p=0.02; BMI: OR = 1.089, CI 95% 1.051-1.129, p < 0.0001). Moreover, two or more diagnostic OGTT glucose levels doubled the risk of insulin therapy (OR = 2.03, IC 95% 1.145-3.612, p=0.016). We did not find any association between ethnicities and neonatal/maternal complications. Conclusions: In our multiethnic GDM population, the need for intensive care and insulin treatment is high in HPMC women although the frequency of adverse peripartum and newborn outcomes does not vary among ethnic groups. The need for insulin therapy should be related to different genetic backgrounds, dietary habits, and Nutrition Transition phenomena. Thus, nutritional intervention and insulin treatment need to be tailored

A "HOLTER" for Parkinson's disease: Validation of the ability to detect on-off states using the REMPARK system

The treatment of Parkinson's disease (PD) with levodopa is very effective. However, over time, motor complications (MCs) appear, restricting the patient from leading a normal life. One of the most disabling MCs is ON-OFF fluctuations. Gathering accurate information about the clinical status of the patient is essential for planning treatment and assessing its effect. Systems such as the REMPARK system, capable of accurately and reliably monitoring ON-OFF fluctuations, are of great interest. Objective To analyze the ability of the REMPARK System to detect ON-OFF fluctuations. Methods Forty-one patients with moderate to severe idiopathic PD were recruited according to the UK Parkinson’s Disease Society Brain Bank criteria. Patients with motor fluctuations, freezing of gait and/or dyskinesia and who were able to walk unassisted in the OFF phase, were included in the study. Patients wore the REMPARK System for 3 days and completed a diary of their motor state once every hour. Results The record obtained by the REMPARK System, compared with patient-completed diaries, demonstrated 97% sensitivity in detecting OFF states and 88% specificity (i.e., accuracy in detecting ON states). Conclusion The REMPARK System detects an accurate evaluation of ON-OFF fluctuations in PD; this technology paves the way for an optimisation of the symptomatic control of PD motor symptoms as well as an accurate assessment of medication efficacy