Challenges in Stellar Population Studies

The stellar populations of galaxies contain a wealth of detailed information. From the youngest, most massive stars, to almost invisible remnants, the history of star formation is encoded in the stars that make up a galaxy. Extracting some, or all, of this informationhas long been a goal of stellar population studies. This was achieved in the last couple of decades and it is now a routine task, which forms a crucial ingredient in much of observational galaxy evolution, from our Galaxy out to the most distant systems found. In many of these domains we are now limited not by sample size, but by systematic uncertainties and this will increasingly be the case in the future. The aim of this review is to outline the challenges faced by stellar population studies in the coming decade within the context of upcoming observational facilities. I will highlight the need to better understand the near-IR spectral range and outline the difficulties presented by less well understood phases of stellar evolution such as thermally pulsing AGB stars, horizontal branch stars and the very first stars. The influence of rotation and binarity on stellar population modeling is also briefly discussed.Comment: Plenary review talk at IAU GA in Rio de Janeiro to be published in the proceedings of IAU Symposium 262. Movies and talk slides available at http://www.strw.leidenuniv.nl/~jarle/IAU0

Developmental dyscalculia and mathematics anxiety: Large population studies

I will review our recent projects which examined a cognitive mathematical deficit (developmental dyscalculia) and an emotional block of mathematical performance (mathematics anxiety) in children. First, in a large study (n=1004) have contrasted several theories of developmental dyscalculia, and found that it was related to weak visuo-spatial memory and weak inhibition skills. In a follow-up study (n=1800) we found that mathematics anxiety was negatively associated with mathematical performance. Most importantly, developmental dyscalculia and mathematics anxiety showed strong dissociation. This suggests that cognitive and emotional blocks of mathematical development need different interventions. Girls were especially prone to developing mathematics anxiety in various countries (Italy, Colombia). I will point to the educational and practical relevance of our studies.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Fish Population Studies

Generally, we hear such questions as "what is the magnitude of our oil sardine or mackerel resources?" "Can we get more catch from these resources?" It is, therefore, proper that we carefully examine what is meant by a fishery resource e. g., oil sardine or mackerel resource. A fishery resource is just like any other natural resource (e. g., mineral resource, hydro-electric resource etc.) which is exploited by man. But at the same time, it differs considerably to character from other types like mineral resources. The coal resource in a region is limited in magnitude, even though sometimes we do not know the magnitude. From this fixed resource we can exploit at any desired rate. The resource will be completely exhausted after a period of time depending on the rate of exploitation. In this sense a mineral resource can be described as a non-renewable natural resource which is liable to get exhausted after some period of time. It is also a static resource because we always know how much of the resource remains, once we know how much has been removed. A fishery resource is very much different in character. It is a self-regulating renewable natural resource. Consider a fish population occupying a certain area of the sea. Now when a certain portion of the population is removed, the remaining portion in the habitat gets better food, more area to move about, and this results in faster growth rate, lesser mortality rates and also the spawns get better chance of survival- The result is that the resource resuscitates itself quickly. Apart from fishing, the population is also affected by many other fishery-independent environmental factors such as available food supply, change in salinity, temperature of the water, change in ocean-currents etc. Thus the fishery resource is a dynamic resource, ever changing due to impact of fishing and other fishery-independent factors