De la población al individuo... y viceversa

De la población al individuo… y viceversa. El estudio de los cambios numéricos en las poblaciones de aves ha fascinado al ser humano desde tiempos históricos. Sin embargo, las poblaciones son entidades complejas formadas por individuos diferentes y sometidas a cambios importantes en el tiempo y en el espacio. La complejidad de los procesos de cambio, los distintos niveles de estructuración demográfica y espacial y las múltiples fuentes de heterogeneidad han dificultado una aproximación ‘intuitiva’ al estudio de sus dinámicas, haciendo necesario el uso de modelos matemáticos. Intentaré ilustrar un viaje por los avances en el estudio de la dinámica de las poblaciones de aves, a través de ideas, modelos y observaciones. Un viaje con sus errores, con sus fórmulas innovadoras o que pasaron desapercibidas hasta su redescubrimiento, con matématicos y naturalistas curiosos en un diálogo interdisciplinar creciente que ha conducido al reconocimiento de la alta complejidad de las poblaciones, producida a partir de los individuos que las componen y sus interacciones.From population to individual… and vice versa. People have been fascinated by the study of numerical changes in bird populations since historical times. Still, populations are complex entities formed by different individuals and subject to important changes in time and space. The complexity of the processes of change, the distinct levels of spatial and demographic structure and the multiple sources of heterogeneity have made an “intuitive” approach to the study of their dynamics difficult, necessitating the use of mathematical models. I will attempt to illustrate a journey through advances in the study of bird population dynamics by way of ideas, models and observations. It is a journey with its errors and innovative formulae, some of which have passed unnoticed until their rediscovery; a journey with its enquiring mathematicians and naturalists in growing interdisciplinary dialogue that has led to recognition of the great complexity of populations, produced by the individuals that composed them and their interactions

Future Perspectives in Acute Myocarditis Complicated by Cardiogenic Shock

Acute myocarditis is an inflammatory disease of the myocardium with a highly variable clinical course. Fulminant myocarditis (FM) represents the most threatening scenario with hemodynamic compromise and cardiogenic shock at presentation. Despite medical advances and the availability of promising mechanical circulatory support (MCS), FM is burdened by a dismal prognosis. Early referral to tertiary hospitals with MCS facilities and prompt diagnosis with endomyocardial biopsy are critical steps toward optimal management. Moreover, beyond supportive care, the prevention of irreversible myocardial damage with immunomodulating therapies must be proven in clinical trials. In this editorial, we briefly describe current evidence and future perspectives regarding the management of myocarditis complicated by cardiogenic shock

Gli effetti del factoring sulle imprese italiane: alcune evidenze empiriche.

The empirical literature about factoring mainly focuses on the reasons why firms use factoring, suggesting the role of many factors such as the age of the firm, the size, the financial structure and the features of the product, of the distribution channels and of the trade relationships, without analyzing the potential effects that the use of factoring may generate on the firm both on the management and the financial structure. This work focus on two level of analysis: a qualitative survey about the insight of the firms with regard to the effect of factoring, that takes into account the answers given by the firms during a previous research, and a quantitative analysis of their balance sheets. This analysis provides interesting results which confirm some of the theories about the effect of the use of factoring on the firms: firms using factoring in a wide, systematic and long-lasting relationship are more able to identify well the benefits on the trade credit relationship and to correctly evaluate the suitability of factoring in respect to those who use it in a occasional or limited fashion. Moreover, results confirm also some of the theoretical previsions about the effect of a "correct" use of factoring on the balance sheet of the firm in terms of profitability, financial structure and, at the end of the day, a better overall performance

Habitat- and density-dependent demography of a colonial raptor in Mediterranean agro-ecosystems

Agricultural intensification is considered the major cause of decline in farmland bird populations, especially in the Mediterranean region. Food shortage increased by the interaction between agricultural intensification and density-dependent mechanisms could influence the population dynamics of colonial birds. Weused demographic data on lesser kestrels (Falco naumanni), a key species of Mediterranean pseudo-steppes, to understand the importance of land-use changes and density-dependent mechanisms in the light of its fluctuating conservation status in the Western Palearctic. Our analysis indicated an important influence of land uses (artichokes, arable and grassland fields) and colony size on kestrel survival rates. The strong habitat effect revealed the unsuitability of intensive arable lands with respect to extensive grasslands for lesser kestrels. Notably, artichokes, a winterintensive crop, proved to be a high-quality habitat as they were associated with survival values equal to those of grassland. This is likely due to prey availability and reveals that non-traditional crops may provide suitable habitats for lesser kestrels. Information theory gave strong support to the negative influence of colony size on fecundity, albeit a small one, for its positive effect on survival probability. The estimated population growth rate was negative for all three habitats, indicating a decline over time and urging conservation actions in all of the areas studied. This decline was much higher in colonies surrounded by arable fields. In sensitivity analyses, λ indicated that adult survival was the parameter with the greatest effect on population growth, followed by survival of fledglings and fecundity. Our study showed howthe costs and benefits of group living interact with agricultural intensification to drive species demography. In addition, we integrated significant information on one of the largest lesser kestrel populations to fine tune the most effective conservation strategy to prevent the collapse of the species in a relevant part of its range

Estimating recruitment and survival in partially monitored populations

In evolutionary and ecological studies, demographic parameters are commonly derived from detailed information collected on a limited number of individuals or in a confined sector of the breeding area. This partial monitoring is expected to underestimate survival and recruitment processes because individuals marked in a monitored location may move to or recruit in an unobservable site. We formulate a multi-event capture-recapture model using E-SURGE software which incorporates additional information on breeding dispersal and the proportion of monitored sites to obtain unbiased estimates of survival and recruitment rates. Using simulated data, we assessed the biases in recruitment, survival and population growth rate when monitoring 10-90% of the whole population in a short- and a long-lived species with low breeding dispersal. Finally, we illustrate the approach using real data from a long-term monitoring program of a colony of Scopoli's shearwaters Calonectris diomedea. We found that demographic parameters estimated without considering the proportion of the area monitored were generally underestimated. These biases caused a substantial error in the estimated population growth rate, especially when a low proportion of breeding individuals were monitored. The proposed capture-recapture model successfully corrected for partial monitoring and provided robust demographic estimates. Synthesis and applications. In many cases, animal breeding populations can only be monitored partially. Consequently, recruitment and immature survival are underestimated, but the extent of these biases depends on the proportion of the area that remains undetected and the degree of breeding dispersal. We present a new method to obtain robust and unbiased measures of survival and recruitment processes from capture-recapture data. The method can be applied to any monitored population regardless of the type of nests (e.g. artificial or natural) or breeding system (e.g. colonial or territorial animals), and it only relies on an estimate of the proportion of the monitored area. The unbiased estimates obtained by this method can be used to improve the reliability of predictions of demographic population models for species' conservation and management.Research funds were provided by the Spanish Ministries of Science, Economy and Competitiveness (refs. BOS2003-01960, CGL2006-04325/BOS, CGL2009-08298, CGL2013-42203-R, JCI-2011-09085)Peer Reviewe

A case of beta-thalassaemia major resistant to standard treatment

We report the case of a 22-year-old woman from Albania, with thalassaemia major, in severe clinical condition who could no longer be transfused due to the occurrence of severe, acute, post-transfusional reactions. After 10 years of treatment, she failed to respond to hydroxyurea. When she received thalidomide, haemoglobin levels increased from 3.7 g/dl to 9 g/dl. Since then, at 22 months of follow-up, the therapy is still effective and well tolerated. The case gives the opportunity to describe the clinical use of thalidomide, and its potential in the management of beta-thalassaemia

Oceanographic drivers and mistiming processes shape breeding success in a seabird

Understanding the processes driving seabirds’ reproductive performance through trophic interactions requires the identification of seasonal pulses in marine productivity.We investigated the sequence of environmental and biological processes driving the reproductive phenology and performance of the storm petrel (Hydrobates pelagicus) in the Western Mediterranean. The enhanced light and nutrient availability at the onset of water stratification (late winter/early spring) resulted in annual consecutive peaks in relative abundance of phytoplankton, zooplankton and ichthyoplankton. The high energy-demanding period of egg production and chick rearing coincided with these successive pulses in food availability, pointing to a phenological adjustment to such seasonal patterns with important fitness consequences. Indeed, delayed reproduction with respect to the onset of water stratification resulted in both hatching and breeding failure. This pattern was observed at the population level, but also when confounding factors such as individuals’ age or experience were also accounted for.We provide the first evidence of oceanographic drivers leading to the optimal time-window for reproduction in an inshore seabird at southern European latitudes, along with a suitable framework for assessing the impact of environmentally driven changes in marine productivity patterns in seabird performance.Research funds were provided by the Spanish Government (refs. BOS2003-01960, CGL2006-04325/BOS, CGL2009 08298, CGL2013-42203-R, JCI-2011-09085), and the European Union (FP7-PEOPLE 2009-IEF-MATERGLOBE)Peer Reviewe

Article No. anbe

Many bird species nest in close association with other bolder and more aggressive birds which provide protection against nest predators. The woodpigeons, Columba palumbus, that nest in poplar plantations in Northern Italy are found almost exclusively clumped around hobby, Falco subbuteo, nests. Woodpigeons settle in the area and build their nests after the hobby has started nesting. We carried out experiments with dummy nests and observations on woodpigeon nests. Dummy woodpigeon nests placed near a hobby's nest suffered less depredation by hooded crows, Corvus corone cornix, than those placed far from it. A logistic regression analysis showed that three variables, hobby nesting stage, distance from the hobby's nest and the hobby's aggressiveness, influenced the probability of nest predation. The degree of protection varied during the hobby's nesting period and was highest when chicks were in the nest. The hobby's aggressiveness against intruders varied both between and within individuals during different nesting phases. The predation rate of dummy nests associated with the falcon was negatively correlated with the aggressiveness score of the hobby during the 6 days of dummy nest exposure. Observations on real nests showed that woodpigeons selected hobbies that had a high fledging success, and a more vigorous defensive behaviour. Clues that would allow woodpigeons to choose the best protector may be early nesting by the hobby and its aggressiveness. Hobbies preyed on adult woodpigeons, but the risk incurred by the woodpigeons was low compared with the very high risk of nest predation in this area

Discard-ban policies can help improve our understanding of the ecological role of food availability to seabirds

ACKNOWLEDGEMENTS Funds for this study were supplied by the Spanish Ministry of Economy and by the European Social Fund (grant ref.: CGL2013-42203-R). The study also received funding from the European Commission’s Horizon 2020 Research and Innovation Programme under Grant Agreement no. 634495 for the project Science, Technology, and Society Initiative to Minimize Unwanted Catches in European Fisheries (MINOUW). MG and ASA are supported by postdoctoral contracts co-funded by the Regional Government of the Balearic Islands and the European Social Fund. Two reviewers helped to improve the manuscript.Peer reviewedPublisher PD