International Trade, as part of the global economy, has suffered consequences crisis originated by pandemic. This paper pretends to analyze effects on exports and imports products services in Spain. The conclusions show that, drastic falls some sectors had a temporary component most cases (especially sanitary esential goods), but other industries (like tourism, hospitality leisure) are still su...

As I grow older, I find myself yearning more and more for a connection between my work and the complex problems facing the world. And unlike most people, I am in a profession where I have the flexibility to choose what I do. Should this yearning influence the kind of research that I pursue? Should it affect how and what I teach my students? At the very least I should vigilantly ponder these que...

We describe a simple, efficient, gentle and inexpensive technique for the introduction of normally impermeant macromolecules into the cytosol of living mammalian cells growing in suspension or attached to the culturing substratum. Loading is achieved by the production of transient, survivable plasma membrane disruptions as cells are passed back and forth through a standard syringe needle or sim...

This paper studies the behavior of leverage ratios in a dynamic trade-off model with real frictions. Firms underutilize debt when financing investment to retain financial flexibility. Underutilization of debt persists even when firms exercise their last investment options, and it is more (less) severe for more back-loaded (front-loaded) investment opportunities. Thus, leverage dynamics cruciall...

Material Handling Equipment (MHE) is widely used to move packaged goods from manufacturing to warehousing, storage, transportation, in both warehouses and distribution centers to retail stores. Moving product between facilities is done by different types of equipment ranging from manually pushed carts to automated vehi­ cles. A considerable amount of research has been conducted to eval­ uate th...

We use game-level data from the Australian Football League (AFL) to examine superstar workers' productivity and pay. By exploiting teams' injury-induced line-up changes between games, we show that, compared with replacement-level players, superstars increase their likelihood of winning away games by approximately 15 percentage points. While then that betting markets appear appropriately price s...

E-commerce is growing rapidly and sales of digital goods represent a substantial portion of all online sales. Several goods such as music and books are now available in a physical and digital format. In a single-period case we compare pricing of digital vs. physical goods and derive an optimal pricing strategy for digital goods in both a general setting without a capacity constraint and a capac...

In this paper we present the solution to a weekly log-truck scheduling problem (LTSP) integrating the routing and scheduling of trucks where all goods are transported in full truckloads. This problem includes aspects such as pick-up and delivery, multiple products, inventory levels, and lunch breaks. The objective is to minimize the overall transportation cost including wait times, and both emp...

Process States: The state of a process describes what the process is going through at a given time. The possible states in the lifetime of a process are: New: When the process is being set up and loaded. Ready: When the process has been loaded in memory and is ready to run, but has not been scheduled on the CPU yet. Run: When the process is executing in the CPU. Wait: When the process needs som...