Introduction: Malaria is among the most significant travel-related infections encountered by travelers to endemic countries in terms of morbidity and mortality. In Qatar, imported malaria has increased over the last 5 years; 493 travel-related cases were confirmed in 2016. In the current study, the knowledge of malaria chemoprophylaxis among physicians in the State of Qatar was...

Many urban areas suffer from traffic congestion. Intuitively, it may seem that a road expansion (e.g., the opening of a new road) should always improve the traffic conditions. However, in reality, a new road can actually worsen traffic congestion. It is therefore extremely important that before we start a road expansion project, we first predict the effect of this project on traffic congestion....

Introduction: Last-minute travelers (LMTs) are a vulnerable group, because it may not be possible to adequately vaccinate them against exposure to infectious diseases. The purpose of this retrospective cross-sectional study was to describe the characteristics of LMTs attending a travel health clinic. Methods: The following data was extracted from records ...

Recent advancements in computing and Geographic Information Systems (GIS) have revolutionized the development of decision support systems (DSS) to study and simulate the future of travel demand in urban areas. While travel demand models have been widely developed and used to inform the urban planning process, very little has been done to explicitly account for the aging of population within suc...

Introduction: Immigrants to the United States who return home to visit friends and relatives (VFRs) have high rates of travel-related infections. The data on VFR utilization of pre-travel health care is inadequate. The objective of this study was to describe the travel patterns and adherence to pre-travel recommendations of VFRs.Methods: This retrospectiv...

In this work we present a method to be used in decision support system (DSS), which solve the Vehicle Routing Problem with Time Windows. In order to find a good estimation of customers’ delivery time, we consider the fluctuations of the travel time. Solving the routing problems with time constraints without taking into account the fluctuations of the travel time during the day, can lead to seri...

Context. Very precise planned space astrometric missions and recent improvements on imaging capabilities require a detailed review of the assumptions of classical astrometric modeling. Aims. We show that Light-Travel Time must be taken into account to model the kinematics of astronomical objects in nonlinear motion, even at stellar distances. Methods. A closed expression to include Light-Travel...

Travellers are at risk of a diverse range of environmental and infectious conditions, some of which may affect the eyes and lead to blindness in severe cases. Travel-related ocular infections include onchocerciasis, leishmaniasis, cysticercosis, trachoma, dengue, loiasis, and leptospirosis. The travel medicine adviser should also recognise other hazards encountered during travel which may adver...

A directed graph with cities as vertices and arcs determined by outgoing (or return) travel represents the mobility component in a population of individuals who travel between n cities. A model with 4 epidemiological compartments in each city that describes the propagation of a disease in this population is formulated as a system of 4n ordinary differential equations. Terms in the system accoun...