On the computation of confluent hypergeometric functions for large imaginary part of parameters b and z

The final publication is available at http://link.springer.com/chapter/10.1007%2F978-3-319-42432-3_30We present an efficient algorithm for the confluent hypergeometric functions when the imaginary part of b and z is large. The algorithm is based on the steepest descent method, applied to a suitable representation of the confluent hypergeometric functions as a highly oscillatory integral, which is then integrated by using various quadrature methods. The performance of the algorithm is compared with open-source and commercial software solutions with arbitrary precision, and for many cases the algorithm achieves high accuracy in both the real and imaginary parts. Our motivation comes from the need for accurate computation of the characteristic function of the Arcsine distribution or the Beta distribution; the latter being required in several financial applications, for example, modeling the loss given default in the context of portfolio credit risk.Peer ReviewedPostprint (author's final draft

Length-weight relationships of demersal fishes from the upper continental slope off Colombia

Parameters of the length–weight relationship of the form W=aLb are presented for 45 demersal fish species caught on the upper continental slope of the Caribbean Sea off Colombia. The b values varied between 2.13 and 4.97, with the mean b = 3.042 (95% CI, 2.887- 3.196)

Sexual dimorphism in bite performance drives morphological variation in chameleons

Phenotypic performance in different environments is central to understanding the evolutionary and ecological processes that drive adaptive divergence and, ultimately, speciation. Because habitat structure can affect an animal's foraging behaviour, anti-predator defences, and communication behaviour, it can influence both natural and sexual selection pressures. These selective pressures, in turn, act upon morphological traits to maximize an animal's performance. For performance traits involved in both social and ecological activities, such as bite force, natural and sexual selection often interact in complex ways, providing an opportunity to understand the adaptive significance of morphological variation with respect to habitat. Dwarf chameleons within the Bradypodion melanocephalum-Bradypodion thamnobates species complex have multiple phenotypic forms, each with a specific head morphology that could reflect its use of either open-or closed-canopy habitats. To determine whether these morphological differences represent adaptations to their habitats, we tested for differences in both absolute and relative bite performance. Only absolute differences were found between forms, with the closed-canopy forms biting harder than their open-canopy counterparts. In contrast, sexual dimorphism was found for both absolute and relative bite force, but the relative differences were limited to the closed-canopy forms. These results indicate that both natural and sexual selection are acting within both habitat types, but to varying degrees. Sexual selection seems to be the predominant force within the closed-canopy habitats, which are more protected from aerial predators, enabling chameleons to invest more in ornamentation for communication. In contrast, natural selection is likely to be the predominant force in the open-canopy habitats, inhibiting the development of conspicuous secondary sexual characteristics and, ultimately, enforcing their overall diminutive body size and constraining performance

Spreading the use of economic methods in coastal risk management: a simple but insightful “calculator”

Navas, F.; Malvárez, G.; Penning-Rowsell, E., and Parker, D.J., 2020. Spreading the use of economic methods in coastal risk management: A simple but insightful "calculator". In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1217–1222. Coconut Creek (Florida), ISSN 0749-0208. European Directives, such as the EU Floods Directive (2007/60/EC) require that decision makers include objective methodologies, such as benefit-cost analysis, in their assessments of flood risk reduction measures. Methodologies to establish a sustainable knowledge framework addressing the costs and benefits of prevention and response to coastal hazards resulting from hydro-meteorological, hydrographic and other natural events and processes (e.g. flooding, beach erosion, cliff erosion, sea level rise) are not homogeneously implemented in the European Union. Until now, investment decisions in this field have been made more on local political imperatives than logical economic risk assessments. This paper aims to overcome some these limitations by demonstrating the usefulness of a simplified benefit-cost methodology and its application to a coastal case where a number of alternative flood risk reduction schemes are considered. The method allows the economically optimal scheme to be identified. The method is discussed within the context of generally poorly comprehended aspects; issues presented in coupling benefit-cost methods with vulnerability and related assessments; and key data uncertainties

Aplicabilidad de las TIG en la generación de escenarios de futuro para una gestión integrada de las zonas costeras

Para una planificación y gestión coherente de las zonas costeras es fundamental que exista una profunda comprensión de las interacciones entre el hombre y el medio físico, siendo preciso integrar la información sobre el conocimiento del medio natural aportada por las diferentes disciplinas científicas, junto con la información del contexto socio-económico, normativo y cultural. Por tanto, la toma de decisiones en los espacios litorales debe apoyarse en instrumentos interdisciplinares, capaces de operar con distintos tipos de datos y abordar situaciones complejas e impredecibles. La simulación de escenarios es una importante herramienta para evaluar desarrollos futuros en sistemas complejos y dinámicos que poseen un número alto de incertidumbres, y por ello es una técnica muy adecuada para la gestión de las zonas costeras. Los escenarios permiten integrar modelos socioeconómicos con modelos físicos, químicos o biológicos, reflejar una amplia gama de tendencias y dinámicas, y trabajar con distintas escalas temporales y espaciales. En el presente artículo se examina el uso actual y el potencial de las TIG en la generación de escenarios de futuro para la gestión integrada de las zonas costeras. Para ello se ha realizado un análisis de su aplicabilidad de las TIG, identificando en qué fases de la elaboración de escenarios se pueden utilizar. Los resultados indican que estas tecnologías tienen un alto potencial y son aplicables en todas las fases de la generación de los escenarios. Una de las fortalezas identificadas es que las TIG incrementan la transparencia y fiabilidad de la generación de escenarios de futuro facilitando los procesos equitativos y participativos de negociación, toma de decisiones y planificación en las zonas costeras.To achieve a coherent planning and management of coastal areas it is necessary having a deep understanding of the interactions existing between human-being and the physical environment, integrating information from different scientific disciplines (hydrology, morphodynamics, soil science, ecology, etc.) and socio-economic, normative and cultural context information. Therefore decision-making in coastal areas must be based on interdisciplinaryinstruments capable of working with different type of data and dealing with complex and unpredictable situations. Scenario-making is one of the most important tools for assessing future developments in complex and dynamic systems which have a high number of uncertainties; thus it is a very suitable approach for coastal zone management. Scenarios can integrate socio-economic models with physical, chemical or biological models, reflect a broad range of trends and dynamics, and work with different temporal and spatial scales. In this paper the current and potential use of Geographical Information Technologies (GIT) is examined in the generation of future scenarios for an integrated management of coastal areas. An analysis of the applicability of the GIT has been done, identifying at which stage of scenario development GIT can be used. The results indicate that GIT have great potential and are applicable at all stages of the scenarios generation. One of the strengths identified is that GIT increase the transparency and reliability of the generation of future scenarios and facilitate equitable and participatory processes of negotiation, decision making and planning in coastal areas

A Greenhouse Tomato Crop Grey Mould Disease Early Warning System

Tomato is a very important crop in the Mediterranean region in general and in Portugal in particular being the production for fresh consumption made essentially in greenhouses. Botrytis cinerea Pers.: Fr. is the causal agent of grey mould disease and is one of the most important diseases affecting greenhouse tomato crops, high relative humidity and the presence of free water on the plant surfaces have been recognized as favourable to the development of this disease. The availability of a early warning system providing to the tomato grower alerts with information of the potential favoured conditions for the disease appearance in its early stages or even before can have a very positive impact in reducing the economic and environmental impacts due to a more rational and efficient disease control management. Today we have the necessary technology to build and launch an Internet based early warning system for grey mould disease in greenhouse tomato crop supported by a wireless sensor network. In this paper a prototype for such a system is presented. From the research conducted until the moment the proposed solution is viable and the next step will be to validate it in the field in different locations and with distinct greenhouses conditions

Design of a Continuous Improvement Model in a Portuguese Food Industry Company – A Case Study

The search for perfection forces organizations to adopt new techniques and approaches, focused on the systematic creation of innovative solutions that facilitate the processes of continuous improvement. In view of this context, there was an opportunity to study the implementation of the Lean philosophy in the production line, at a processed food organization. A continuous improvement model was designed for an organizational system, combining tools used in both TRIZ methodology and Lean philosophy. Several Lean tools are used in the model in order to support problem formulation, e.g. Brainstorming, 5 Whys, Pareto Diagram, Ishikawa Diagram, Plan-Do-Check-Act (PDCA) Cycle. And the Kano Model integrated in the proposed model allows assessing employee satisfaction at a later stage than the implementation of previously found solutions. In case the problems identified are not very complex, were resorted to the use of both TRIZ and Lean techniques, such as cause/effect databases, the 40 problem solving TRIZ principles, visual management, 5S's or line balancing. But if the problems identified are more complex, which means with an inventive issue to be solved, Matrix of Contradictions and S-Field Analysis TRIZ tools proved to be more appropriate to find the proper solution. With the case study carried out, it was noted that the proposed model proved to be very useful as a roadmap for the implementation of Lean and TRIZ tools in the continuous improvement of industrial products, services and processes should be the ways to continually minimize them in a company.authorsversionpublishe

The COVID-19 Diagnostic Technology Landscape: Efficient Data Sharing Drives Diagnostic Development

Work at the Brazilian groups was partially funded by grants fromMCTIC, CNPq, CAPES, and FAPESB. LP was recipient of a research fellowship from CNPq