Density dependence of daily activity in three ungulate species.

Daily activity in herbivores reflects a balance between finding food and safety. The safety-in-numbers theory predicts that living in higher population densities increases safety, which should affect this balance. High-density populations are thus expected to show a more even distribution of activity-that is, spread-and higher activity levels across the day.

Uncovering the different scales in deer-forest interactions.

Deer are regarded to be a keystone species as they play a crucial role in the way an ecosystem functions. Most deer-forest interaction studies apply a single scale - process of analyzing ecological interactions by only taking into account one dependent variable - to understand how deer browsing behavior shapes different forest components, but they overlook the fact that forests respond to multiple scales simultaneously. This research evaluates the effect of browsing by wild deer on temperate and boreal forests at different scales by synthesizing seminal papers, specifically (a) what are the effects of deer population density in forest regeneration? (b) What are the effects of deer when forests present diverging spatial characteristics? (c) What are the effects on vegetation at different temporal scales? and (d) What are the hierarchical effects of deer when considering other trophic levels? Additionally, a framework based on modern technology is proposed to answer the multiscale research questions previously identified.

[Síndrome de Paget-Schrötter: presentación de cuatro casos].

Deep vein thrombosis (DVT) of the upper limb is a rare entity, estimated to account for 10% of all cases of DVT. Classically, they are classified into primary (idiopathic, due to subclavian vein compression or exercise related) and secondary (cancer, thrombophilia, trauma, shoulder surgery, associated to venous catheters or due to hormonal causes). The Paget- Schrötter syndrome is a primary thrombosis of the subclavian vein in the subclavian-axillary junction, related either to repetitive movements or to exercise; leading to microtrauma in the endothelium with consequent activation of the coagulation cascade.