An Observational Overview of Solar Flares

We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

Heterpcomplex formation between metastasis-related protein S100A4 (Mts 1) and S100A1 as revealed by the yeast two-hybrid system

AbstractS100A4 (Mts1) is a Ca2+-binding protein of the S100 family. This protein plays an important role in promoting tumor metastasis. In order to identify S100A4 interacting proteins, we have applied the yeast two-hybrid system as an in vivo approach. By screening a mouse mammary adenocarcinoma library, we have demonstrated that S100A4 forms a heterocomplex with S100A1, another member of the S100 family. The non-covalent heterodimerization was confirmed by fluorescence spectroscopy and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Mutational analysis revealed that replacement of Cys76 and/or Cys81 of S100A4 by Ser abolishes the S100A4/S100A1 heterodimerization, but does not affect the S100A4 homodimerization in vivo

Basis of selective predation by the aquatic larvae of the salamander, Ambystoma tigrinum

The effect of several factors on feeding selectivity by three size classes of larvae of Ambystoma tigrinum (Green) was examined. Five types of invertebrate prey were used: Chaoborus, Daphnia, damselflies, Hyalella and water boatmen. Five variables were examined in relation to the electivity indices associated with each prey type: ease of prey consumption, ease of prey capture, relative prey size, prey activity, and microhabitat overlap. No single variable explained the observed electivity. For small larvae (snout-vent length, SVL,6.5cm), ease of prey consumption, prey activity, and relative prey size predicted electivity values. However, none of the measured variables was related to electivity values found for medium sized larvae (SVL \u3e3.5 and \u3c5.5cm)

Selective predation by Lestes (Odoiiata, Lestidae) on littoral microcrustacea

Two experimental approaches were used to examine the predation risk of six littoral cladoceran and ostracod species to two size classes of the damselfly Lestes sp. Behavioural observations were conducted in a 2–1 arena and predation rate experiments in 1–1 jars in the laboratory.  Behavioural observations revealed that attack and capture efficiencies by Lestes were higher on smaller cladocerans (Polyphemus and Ceriodaphnia) than on other taxa. Small Lestes had little success ingesting the small ostracod Cypridopsis, whereas larger Lestes captured and ate it easily.  Predation‐rate experiments showed that Lestes has a clear preference for smaller cladocerans over both a large cladoceran Simocephatus and all three ostracods (Cypricercus, Cyclocypris, and Cypridopsis). Most Lestes were unable to consume the larger Cypricercus.  Attack rates and predation rates were highly variable among individual predators.  These data indicate that damselfly larvae are size selective and consume all but very large cladocerans more readily than ostracods. Copyright © 1993, Wiley Blackwell. All rights reserve