The Hvar survey for roAp stars: II. Final results (Research Note)

The 60 known rapidly oscillating Ap (roAp) stars are excellent laboratories to test pulsation models in the presence of stellar magnetic fields. Our survey is dedicated to search for new group members in the Northern Hemisphere. We attempt to increase the number of known chemically peculiar stars that are known to be pulsationally unstable. About 40 h of new CCD photometric data of 21 roAp candidates, observed at the 1m Austrian-Croatian Telescope (Hvar Observatory) are presented. We carefully analysed these to search for pulsations in the frequency range of up to 10mHz. No new roAp star was detected among the observed targets. The distribution of the upper limits for roAp-like variations is similar to that of previoius similar efforts using photomultipliers and comparable telescope sizes. In addition to photometric observations, we need to consolidate spectroscopic information to select suitable targets.Comment: 8 pages, 5 figures, accepted by Astronomy & Astrophysic

Syntactic Complexity and Frequency in the Neurocognitive Language System

Prominent neurobiological models of language follow the widely accepted assumption that language comprehension requires two principal mechanisms: a lexicon storing the sound-to-meaning mapping of words, primarily involving bilateral temporal regions, and a combinatorial processor for syntactically structured items, such as phrases and sentences, localized in a left-lateralized network linking left inferior frontal gyrus (LIFG) and posterior temporal areas. However, recent research showing that the processing of simple phrasal sequences may engage only bilateral temporal areas, together with the claims of distributional approaches to grammar, raises the question of whether frequent phrases are stored alongside individual words in temporal areas. In this fMRI study, we varied the frequency of words and of short and long phrases in English. If frequent phrases are indeed stored, then only less frequent items should generate selective left frontotemporal activation, because memory traces for such items would be weaker or not available in temporal cortex. Complementary univariate and multivariate analyses revealed that, overall, simple words (verbs) and long phrases engaged LIFG and temporal areas, whereas short phrases engaged bilateral temporal areas, suggesting that syntactic complexity is a key factor for LIFG activation. Although we found a robust frequency effect for words in temporal areas, no frequency effects were found for the two phrasal conditions. These findings support the conclusion that long and short phrases are analyzed, respectively, in the left frontal network and in a bilateral temporal network but are not retrieved from memory in the same way as simple words during spoken language comprehension.This research was supported by an Advanced Investigator grant to W. M. W. from the European Research Council (AdG 230570 NEUROLEX) and by MRC Cognition and Brain Sciences Unit (CBSU) funding to W. M. W. (U.1055.04.002.00001.01). Com- puting resources were provided by the MRC CBSU

Systemic Character of Legionnaires’ Disease – A Murine Model

In contrast to lung infection caused by Legionella pneumophila, little is known about the pathogenesis of this disease in other organs. In this study, we analyzed the number of colony forming units (CFU) of legionellae not only in lungs but also in EDTA plasma, liver, spleen and kidneys. The number of CFU was determined 2, 24, 48, 72 and 168 h after intratracheal inoculation. Results showed that the inflammatory response was mostly pronounced in lungs. Legionellae, however, were also found in EDTA plasma and all the other investigated organs. The duration of infection was most protracted in lungs, with persistence for at least 168 h. In the remaining organs, legionellae were found for a maximum of 72 h after inoculation. Besides the culture methods used for detection of CFU we also used LightCycler (LC) PCR to confirm the presence of bacteria in the blood of intratracheally infected mice. By this method the bacterial DNA could be detected during the first two days of post infection

Formation and Interaction of Membrane Tubes

We show that the formation of membrane tubes (or membrane tethers), which is a crucial step in many biological processes, is highly non-trivial and involves first order shape transitions. The force exerted by an emerging tube is a non-monotonic function of its length. We point out that tubes attract each other, which eventually leads to their coalescence. We also show that detached tubes behave like semiflexible filaments with a rather short persistence length. We suggest that these properties play an important role in the formation and structure of tubular organelles.Comment: 4 pages, 3 figure

Reactive Dye Degradation by AOPs; Development of a Kinetic Model for UV/H2O2 Process

An application of UV/H2O2 process for the treatment of model wastewater containing organic reactive azo dye C.I. Reactive Blue 137 (RB137) was studied. The efficiency of applied process for decolorization and mineralization of RB137 model solution is discussed. The influence of operating process parameters, initial pH and initial concentration of H2O2, as well as initial dye mass concentration on process effectiveness was investigated. Both direct UV photolysis and OH radical attack were assumed as RB137 degradation mechanisms and a detailed kinetic model for dye degradation by UV/H2O2 process was proposed. The predicted system behavior was compared with experimentally obtained results of decolorization and mineralization of RB137 wastewater. A sensitivity analysis for the evaluation of importance of each reaction used in the model development was also included

Accumulation of driver and passenger mutations during tumor progression

Major efforts to sequence cancer genomes are now occurring throughout the world. Though the emerging data from these studies are illuminating, their reconciliation with epidemiologic and clinical observations poses a major challenge. In the current study, we provide a novel mathematical model that begins to address this challenge. We model tumors as a discrete time branching process that starts with a single driver mutation and proceeds as each new driver mutation leads to a slightly increased rate of clonal expansion. Using the model, we observe tremendous variation in the rate of tumor development - providing an understanding of the heterogeneity in tumor sizes and development times that have been observed by epidemiologists and clinicians. Furthermore, the model provides a simple formula for the number of driver mutations as a function of the total number of mutations in the tumor. Finally, when applied to recent experimental data, the model allows us to calculate, for the first time, the actual selective advantage provided by typical somatic mutations in human tumors in situ. This selective advantage is surprisingly small, 0.005 +- 0.0005, and has major implications for experimental cancer research

Editorial: Morphologically Complex Words in the Mind/Brain

In most languages, sentences can be broken down into words, which themselves can be further decomposed into units that contain meaning of their own, so-called morphemes (e.g., “play” or plural form “-s”). Morphemes are the main building blocks and tools, which we use to create and change words. The representation of morphologically complex words (inflected, derived, and compound) in the mental lexicon and their neurocognitive processing has been a vigorously investigated topic in psycholinguistics and the cognitive neuroscience of language. Are morphologically complex words such as “player” and “plays” decomposed into their constituents (i.e., into their stem “play” and plural suffix “-s” or agentive suffix “-er”) or are they processed and represented holistically (“player” and “plays”)? Despite extensive research, many important questions remain unanswered. Our Research Topic addresses several currently unresolved topics on the time-course of morphological analysis and the relationship between form and meaning information in morphological parsing. The studies also seek answers to the questions of how inflections and derivations differ in the way they are handled by the mental lexicon, how compound words are recognized and produced, as well as how morphologically complex words are processed within the bilingual mental lexicon, as well as by different clinical populations.AL is funded by Lundbeck Foundation (PI Yury Shtyrov) and Kone Foundation. ML is funded by Academy of Finland (grant #288880) and HC holds Alexander-von-Humboldt Professorship