Friends or Foes? The Problem of South Florida’s Invasive Mangroves

A recent global review on the impacts of climate change on mangroves concluded that different regions will experience varying degrees of impacts due to the variability of expected changes in climate (shifts in precipitation, frequency and intensity of storms, droughts, sea level rise, change of ocean currents, increases in CO2 concentrations, etc.) and the variety of types and mangrove assemblages growing in these regions, including different species composition of mangrove forests. In North America and the Caribbean, these changes are dependent upon a predicted higher frequency (and intensity) of tropical storms, sea level rise, changes in patterns of precipitation, and higher temperatures. Located at the land-sea interface, mangroves in this region are expected to expand their ranges poleward (towards North Florida), or migrate into other coastal ecosystems (e.g., the Everglades), provided no natural or urban center barriers are present to prevent this expansion. If rains increase, as is anticipated, along the United States-Mexico border, mangroves may likely begin to thrive in places currently occupied by unvegetated salt flats. However, a lack of rain may also be of benefit in areas such as Louisiana where marsh diebacks have been linked to droughts, which directly increases the likelihood of mangrove migrations into these ecosystems. Given the services that mangroves provide and the legal protections that mangroves receive, it is shocking to discover that their future existence may be compromised or threatened. Certainly, the greatest threats to mangroves in Florida are from direct and indirect human impacts of development, including pollution and habitat destruction. Mangroves may also be naturally damaged and destroyed from disturbance events such as tropical storms and hurricanes. However, a new threat to native mangroves has recently emerged: the introduction of invasive mangrove species. These non-native species may threaten the ecosystem dynamics of mangrove forests and may alter the natural coastal landscape of South Florida unless eradicated

3D human pose estimation from depth maps using a deep combination of poses

Many real-world applications require the estimation of human body joints for higher-level tasks as, for example, human behaviour understanding. In recent years, depth sensors have become a popular approach to obtain three-dimensional information. The depth maps generated by these sensors provide information that can be employed to disambiguate the poses observed in two-dimensional images. This work addresses the problem of 3D human pose estimation from depth maps employing a Deep Learning approach. We propose a model, named Deep Depth Pose (DDP), which receives a depth map containing a person and a set of predefined 3D prototype poses and returns the 3D position of the body joints of the person. In particular, DDP is defined as a ConvNet that computes the specific weights needed to linearly combine the prototypes for the given input. We have thoroughly evaluated DDP on the challenging 'ITOP' and 'UBC3V' datasets, which respectively depict realistic and synthetic samples, defining a new state-of-the-art on them.Comment: Accepted for publication at "Journal of Visual Communication and Image Representation

PKI Scalability Issues

This report surveys different PKI technologies such as PKIX and SPKI and the issues of PKI that affect scalability. Much focus is spent on certificate revocation methodologies and status verification systems such as CRLs, Delta-CRLs, CRS, Certificate Revocation Trees, Windowed Certificate Revocation, OCSP, SCVP and DVCS.Comment: 23 pages, 2 figure

Existence and uniqueness of nontrivial collocation solutions of implicitly linear homogeneous Volterra integral equations

We analyze collocation methods for nonlinear homogeneous Volterra-Hammerstein integral equations with non-Lipschitz nonlinearity. We present different kinds of existence and uniqueness of nontrivial collocation solutions and we give conditions for such existence and uniqueness in some cases. Finally we illustrate these methods with an example of a collocation problem, and we give some examples of collocation problems that do not fit in the cases studied previously.Comment: 18 pages, 4 figure