Do metal mixture insults to the soil invisible majority reduce ecosystem service quality?

Non-Peer Reviewe

Review of the occurrence and management of <i>Sotalia</i> bycatch in Central and South American coastal and riverine fisheries: priorities for immediate action

Despite the fact that cetacean bycatch has been acknowledged as the “greatest immediate and well documented threat to the survival of cetacean species and populations… …progress at reducing the scale and conservation impact of cetacean bycatch has been slow, sporadic, and limited to a few specific fisheries or circumstances “. In this paper, we 1) Review the occurrence of Sotalia bycatch all along its distribution area, 2) Examine how the problem has been addressed in some areas and 3) Outline some priority actions for conservation of the genus regarding management of bycatch issues. A recent review of cetacean bycatch in the Wider Caribbean Region indicates that mortality of Sotalia in fisheries-related operations with gillnets occurs in Colombia, French Guyana, Honduras, Surinam and Venezuela. Bycatch is also reported in Brazil, Nicaragua and Peru. Some mitigative measures including a ban on fisheries in protected areas, monitoring programs and field surveys for evaluation of bycatch have been made or are planned in Costa Rica and Venezuela. In Brazil, bycatch of Sotalia has been widely documented in coastal areas and also in the Amazon River Basin. In this country, an official action plan for the conservation of aquatic mammals includes specific recommendations to evaluate the impact of bycatch and to develop mitigative measures. According to recent statistics, most of cetacean bycatch worldwide occurs in gillnet fisheries. A precautionary approach suggests that – to protect Sotalia and other cetacean populations-these fisheries should be either regulated, monitored, limited or -in some instances – banned, taking into account that creative solutions should be provided by means of collaborative efforts between resource managers, fishermen, scientists and interested parties. On the other side, because of the socioeconomic aspects involved in such a decision, appropriate alternatives and/or incentives as well as local characteristics of some fisheries must be properly considered

A Quadratic Programming Approach to Quasi-Static Whole-Body Manipulation

This paper introduces a local motion planning method for robotic systems with manipulating limbs, moving bases (legged or wheeled), and stance stability constraints arising from the presence of gravity. We formulate the problem of selecting local motions as a linearly constrained quadratic program (QP), that can be solved efficiently. The solution to this QP is a tuple of locally optimal joint velocities. By using these velocities to step towards a goal, both a path and an inverse-kinematic solution to the goal are obtained. This formulation can be used directly for real-time control, or as a local motion planner to connect waypoints. This method is particularly useful for high-degree-of-freedom mobile robotic systems, as the QP solution scales well with the number of joints. We also show how a number of practically important geometric constraints (collision avoidance, mechanism self-collision avoidance, gaze direction, etc.) can be readily incorporated into either the constraint or objective parts of the formulation. Additionally, motion of the base, a particular joint, or a particular link can be encouraged/discouraged as desired. We summarize the important kinematic variables of the formulation, including the stance Jacobian, the reach Jacobian, and a center of mass Jacobian. The method is easily extended to provide sparse solutions, where the fewest number of joints are moved, by iteration using Tibshirani’s method to accommodate an l_1 regularizer. The approach is validated and demonstrated on SURROGATE, a mobile robot with a TALON base, a 7 DOF serial-revolute torso, and two 7 DOF modular arms developed at JPL/Caltech

Towards a comprehensive taxonomy for characterizing robots

Every day a new robot is developed with advanced characteristics and technical qualities. The increasingly rapid growth of robots and their characteristics demands bridging between the application requirements and the robot specifications. This process requires a supporting conceptual structure that can capture as many robot qualities as possible. Presenting robot characteristics through the proposed conceptual structure would enable designers to optimize robot capabilities against application requirements. It would also help application developers to select the most appropriate robot. Without a formal structure, an accurate linking between the robot domain and the application domain is not possible. This paper presents a novel theoretical representation that can capture robot features and capabilities and express them as descriptive dimensions to be used to develop a capability profile. The profile is intended to unify robot description and presentation. The proposed structure is reinforced with several layers, sections, categorizations and levels to allow a detailed explanation of robot characteristics. It is hoped that the proposed structure will influence the design, development, and testing of robots for specific applications. At the same time, it would help in highlighting the corresponding outlines in robot application requirements

Microparasites and their potential impact on the population dynamics of small cetaceans from South America: a brief review. Document SC/59/DW8, Scientific Committee, International Whaling Commission, Anchorage, Alaska, 4-14 May 2007

We briefly review the pathology, epidemiology and molecular biology of cetacean viruses (including morbilli, papilloma and pox) and Brucella spp. encountered in South America. Antibodies against cetacean morbillivirus were detected (by iELISAs and virus neutralisation tests) in SE Pacific and SW Atlantic delphinids. Morbilliviruses are possibly enzootic in Lagenorhynchus obscurus and offshore Tursiops truncates from Peru and in Lagenodelphis hosei from Brazil and Argentina, but no morbillivirus antibodies were found in inshore small cetaceans. Papillomaviruses cause genital warts in at least three odontocete species in Peru. Two Phocoena spinipinnis papillomaviruses (PsPVs) were found in warts of Burmeister’s porpoises; one (PsPV-1) was cloned and characterized. Half of porpoises had developed genital warts, while in 10% of males the lesions were sufficiently numerous and severe to at least hamper, if not impede, copulation. High titers of cowpox virus neutralising antibodies were detected in Peruvian D. capensis, T. truncatus, L. obscurus and P. spinipinnis in 1993-1995. The high prevalence of orthopoxvirus neutralising antibodies with high titres indicates common infection by poxviruses antigenically related to cowpox virus, the probable causative agents of tattoo skin disease. Cetacean poxviruses may cause significant mortaliy among neonates and calves unprotected by maternal immunity. In Peru, Brucella spp. antibodies were detected (competitive ELISA) in D. capensis, T. truncatus, L. obscurus and P. spinipinnis. Brucellosis is likely enzootic in the latter two species, and may lead to orchitis and bone lesions in L. obscurus and D. capensis. The enzootic circulation of brucellae in L. obscurus and P. spinipinnis may constitute a measurable limiting factor among the environmental variables affecting population dynamics. Also, widespread Brucella spp. infection in several Peruvian odontocetes has public health implications (zoonosis), considering frequent manipulation of carcases and consumption of meat. Extrinsic anthropogenic factors may not only exacerbate the consequences of viral infections on the health of a particular individual, but also operate at the population level

Exploring novel arterio-venous graft designs to reduce vascular access failure risk

Although arterio-venous grafts (AVGs) are the second best option as permanent vascular access for hemodialysis, this solution is still affected by a relevant failure rate associated with neointimal hyperplasia (IH), mainly located at the venous anastomosis, where abnormal hemodynamics occurs. In this study we use computational fluid dynamics (CFD) to investigate the impact of six innovative AVG designs on reducing the IH risk at the distal anastomosis in AVGs. Findings from simulations clearly show that using a helical shaped flow divider located in the venous side of the graft could assure a reduced hemodynamic risk of failure at the distal anastomosis, with a clinically irrelevant increase in pressure drop over the graft

Robots that can adapt like animals

As robots leave the controlled environments of factories to autonomously function in more complex, natural environments, they will have to respond to the inevitable fact that they will become damaged. However, while animals can quickly adapt to a wide variety of injuries, current robots cannot "think outside the box" to find a compensatory behavior when damaged: they are limited to their pre-specified self-sensing abilities, can diagnose only anticipated failure modes, and require a pre-programmed contingency plan for every type of potential damage, an impracticality for complex robots. Here we introduce an intelligent trial and error algorithm that allows robots to adapt to damage in less than two minutes, without requiring self-diagnosis or pre-specified contingency plans. Before deployment, a robot exploits a novel algorithm to create a detailed map of the space of high-performing behaviors: This map represents the robot's intuitions about what behaviors it can perform and their value. If the robot is damaged, it uses these intuitions to guide a trial-and-error learning algorithm that conducts intelligent experiments to rapidly discover a compensatory behavior that works in spite of the damage. Experiments reveal successful adaptations for a legged robot injured in five different ways, including damaged, broken, and missing legs, and for a robotic arm with joints broken in 14 different ways. This new technique will enable more robust, effective, autonomous robots, and suggests principles that animals may use to adapt to injury

Energy Dependence of the NN t-matrix in the Optical Potential for Elastic Nucleon-Nucleus Scattering

The influence of the energy dependence of the free NN t-matrix on the optical potential of nucleon-nucleus elastic scattering is investigated within the context of a full-folding model based on the impulse approximation. The treatment of the pole structure of the NN t-matrix, which has to be taken into account when integrating to negative energies is described in detail. We calculate proton-nucleus elastic scattering observables for $^{16}$O, $^{40}$Ca, and $^{208}$Pb between 65 and 200 MeV laboratory energy and study the effect of the energy dependence of the NN t-matrix. We compare this result with experiment and with calculations where the center-of-mass energy of the NN t-matrix is fixed at half the projectile energy. It is found that around 200 MeV the fixed energy approximation is a very good representation of the full calculation, however deviations occur when going to lower energies (65 MeV).Comment: 11 pages (revtex), 6 postscript figure