First data on batch fecundity and relative fecundity of Sardina pilchardus (Walbaum, 1792) (Clupeidae) in the south-western Adriatic Sea

Se ha determinado por primera vez la fecundidad parcial y relativa de Sardina pilchardus (Walbaum, 1792) en las aguas del bajo Adriático con el método de los ovocitos hidratados. Las muestras han sido recogidas de la propia flota comercial y de embarcaciones alquiladas y equipadas con red de arrastre pelágico a la pareja, red de arrastre semipelágico a la pareja o red de cerco con jareta durante el periodo de reproducción. Se han estudiado diferentes modelos de regresión entre la fecundidad parcial y el peso de las hembras sin ovarios. El mejor ajuste corresponde a una regresión lineal. Se ha calculado también la fecundidad relativa (número de ovocitos por gramo de hembra sin ovarios) y se ha confrontado con la de otros clupeiformes.The batch fecundity and relative fecundity of Sardina pilchardus (Walbaum, 1792) have been determined for the first time in the waters of the Lower Adriatic Sea using the hydrated oocyte method. The samples were collected from the commercial fleet and chartered boats equipped with midwater pair trawls, midwater otter trawls and purse seine during the reproductive period. Various regression models were studied, to express the relationship between the batch fecundity and the weight of ovary-free females. The linear model proved to be the best one, because of its simplicity. Relative batch fecundity (number of hydrated oocytes per gram from ovary-free females) was also studied, and compared with that of other clupeiforms.Instituto Español de Oceanografí

Swarm robotics in wireless distributed protocol design for coordinating robots involved in cooperative tasks

The mine detection in an unexplored area is an optimization problem where multiple mines, randomly distributed throughout an area, need to be discovered and disarmed in a minimum amount of time. We propose a strategy to explore an unknown area, using a stigmergy approach based on ants behavior, and a novel swarm based protocol to recruit and coordinate robots for disarming the mines cooperatively. Simulation tests are presented to show the effectiveness of our proposed Ant-based Task Robot Coordination (ATRC) with only the exploration task and with both exploration and recruiting strategies. Multiple minimization objectives have been considered: the robots' recruiting time and the overall area exploration time. We discuss, through simulation, different cases under different network and field conditions, performed by the robots. The results have shown that the proposed decentralized approaches enable the swarm of robots to perform cooperative tasks intelligently without any central control

Comparison of bio-inspired algorithms applied to the coordination of mobile robots considering the energy consumption

Many applications, related to autonomous mobile robots, require to explore in an unknown environment searching for static targets, without any a priori information about the environment topology and target locations. Targets in such rescue missions can be fire, mines, human victims, or dangerous material that the robots have to handle. In these scenarios, some cooperation among the robots is required for accomplishing the mission. This paper focuses on the application of different bio-inspired metaheuristics for the coordination of a swarm of mobile robots that have to explore an unknown area in order to rescue and handle cooperatively some distributed targets. This problem is formulated by first defining an optimization model and then considering two sub-problems: exploration and recruiting. Firstly, the environment is incrementally explored by robots using a modified version of ant colony optimization. Then, when a robot detects a target, a recruiting mechanism is carried out to recruit a certain number of robots to deal with the found target together. For this latter purpose, we have proposed and compared three approaches based on three different bio-inspired algorithms (Firefly Algorithm, Particle Swarm Optimization, and Artificial Bee Algorithm). A computational study and extensive simulations have been carried out to assess the behavior of the proposed approaches and to analyze their performance in terms of total energy consumed by the robots to complete the mission. Simulation results indicate that the firefly-based strategy usually provides superior performance and can reduce the wastage of energy, especially in complex scenarios

Fujian Tulou Rammed Earth Structures: Optimizing Restoration Techniques Through Participatory Design and Collective Practices

Fujian Tulou is a significant part of the international built heritage. Renovation and strengthening of existing Haka Tulou's earth constructions can ensure a better quality of life for their residents, as well as contribute to a long-lasting prominence of China's heritage. Previous studies of Fujian Tulou mainly cover habitation patterns, construction features and architectural details. In this research a layout has been summarized of causes of deterioration, pathology of structure, focused on the buildings' conservation value and restoration, in terms of history, culture and construction technologies. Out of Fujian's more than 3,000 Tulou, only a few dozen have been awarded the status of World Heritage Sites by UNESCO. Along with that status, the 46 buildings chosen for the award. The buildings which belong to UNESCO's heritage are on list of possible restoration while the rest remain in disintegration and the villages are getting vacant through years. The answer for the restoration could be found through participation and team work of experts and habitants. A Tulou is usually inhabited by one family clan for several generations, and the enclosed structure allows to the members of the community to work together and participate in a common goal.Therefore, it is necessary to find new intervention techniques for these earthen buildings, or to adapt those already existing - and proved - to the specific characteristics of the material. This is the context in which the present research aims at contributing to the development of grouting and stitching the cracks by means of earthen mortar in rammed earth walls, as collective restoration techniques

Optimal Design of Elastic Circular Plane Arches

Arches represent a structural system adopted in construction practice for thousand years, and they are still widely adopted if large spans have to be covered. The structural efficiency of arches principally depends on the minimization of the eccentricity of the pressure curve, which allow us to reduce their structural weight. Despite the millenarian use and a very abundant literature, there is still scope for design optimization of arches. This study is framed within this context and is focused on plane circular arches under uniformly distributed vertical load and self-weight. The arches are elastically clamped at both end sections. A semianalytical approach is developed to minimize the volume, with the aim of determining the fundamental mechanical parameters governing the optimal design. Finally, the results are charted to allow their use in a design process

Infectious disease outbreaks among forcibly displaced persons: an analysis of ProMED reports 1996-2016

Background: The United Nations Refugee Agency (UNHCR) estimates the number of forcibly displaced people increased from 22.7 million people in 1996 to 67.7 million people in 2016. Human mobility is associated with the introduction of infectious disease pathogens. The aim of this study was to describe the range of pathogens in forcibly displaced populations over time using an informal event monitoring system. Methods: We conducted a retrospective analysis of ProMED, a digital disease monitoring system, to identify reports of outbreak events involving forcibly displaced populations between 1996 and 2016. Number of outbreak events per year was tabulated. Each record was assessed to determine outbreak location, pathogen, origin of persons implicated in the outbreak, and suspected versus confirmed case counts. Results: One hundred twenty-eight independent outbreak events involving forcibly displaced populations were identified. Over 840,000 confirmed or suspected cases of infectious diseases such as measles, cholera, cutaneous leishmaniasis, dengue, and others were reported in 48 destination countries/territories. The average rate of outbreak events concerning forcibly displaced persons per total number of reports published on ProMED per year increased over time. The majority of outbreak events (63%) were due to acquisition of disease in the destination country. Conclusion: This study found that reports of outbreak events involving forcibly displaced populations have increased in ProMED. The events and outbreaks detected in this retrospective review underscore the importance of capturing displaced populations in surveillance systems for rapid detection and response