1,718 research outputs found
Statistical analysis of the growth and morphology of the filamentous microbe Streptomyces coelicolor
Analysis of the Swift Gamma-Ray Bursts duration
Two classes of gamma-ray bursts have been identified in the BATSE catalogs
characterized by durations shorter and longer than about 2 seconds. There are,
however, some indications for the existence of a third type of burst. Swift
satellite detectors have different spectral sensitivity than pre-Swift ones for
gamma-ray bursts. Therefore it is worth to reanalyze the durations and their
distribution and also the classification of GRBs. Using The First BAT Catalog
the maximum likelihood estimation was used to analyzed the duration
distribution of GRBs. The three log-normal fit is significantly (99.54 %
probability) better than the two for the duration distribution. Monte-Carlo
simulations also confirm this probability (99.2 %).Comment: NANJING GAMMA-RAY BURST CONFERENCE 200
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Evaluation of moisture sources for the Central European summer flood of May/June 2013 based on regional climate model simulations
Heavy precipitation affected Central Europe in May/June 2013, triggering damaging floods both on the Danube and the Elbe rivers. Based on a modelling approach with COSMO-CLM, moisture fluxes, backward trajectories, cyclone tracks and precipitation fields are evaluated for the relevant time period 30 May–2 June 2013. We identify potential moisture sources and quantify their contribution to the flood event focusing on the Danube basin through sensitivity experiments: Control simulations are performed with undisturbed ERA-Interim boundary conditions, while multiple sensitivity experiments are driven with modified evaporation characteristics over selected marine and land areas. Two relevant cyclones are identified both in reanalysis and in our simulations, which moved counter-clockwise in a retrograde path from Southeastern Europe over Eastern Europe towards the northern slopes of the Alps. The control simulations represent the synoptic evolution of the event reasonably well. The evolution of the precipitation event in the control simulations shows some differences in terms of its spatial and temporal characteristics compared to observations. The main precipitation event can be separated into two phases concerning the moisture sources. Our modelling results provide evidence that the two main sources contributing to the event were the continental evapotranspiration (moisture recycling; both phases) and the North Atlantic Ocean (first phase only). The Mediterranean Sea played only a minor role as a moisture source. This study confirms the importance of continental moisture recycling for heavy precipitation events over Central Europe during the summer half year
Repeated Testing Sessions and Scholastic Aptitude in College Students’ Metacognitive Accuracy
We performed three experiments to examine the effects of repeated study–judgement–test sessions on metacognitive monitoring, and to see if better students (those with higher Scholastic Aptitude Test or SAT scores) outperform low SAT students. In all experiments, mean metacognitive accuracy (bias scores and Gamma correlations) did improve with practice. Most improvement involved students’ ability to predict which items would not be recalled later. In addition, students with high SAT scores recalled more items, were less overconfident, and adjusted their predictions more effectively. Thus, high SAT students may be able to adjust their metacognitive monitoring effectively without feedback, but low SAT students appear unlikely to do so. Educators may need to devise more explicit techniques to help low SAT students improve their metacognitive monitoring during the course of a semester
Distribution and Intracellular Localization of Titanium in Plants After Titanium Treatment
The physiological role of titanium in plants has not been elucidated yet, but a higher rate of growth , greater chlorophyll content and higher productivity, among others , may be attributed to this element. We have investigated the distribution of titanium in wheat seedlings after Titavit (a Ti ·ascorbate containing plant conditioner) treatment applied either through the leaf or through the root. In field experiments, we also sprayed spinach plants with Titavit. We have found a practically unidirectional tran slocation of Ti from the shoot into the root, and a preferential local ization of Ti in the nuclear cell fraction as seen by JCP-AES (inductively coupled plasma atomic emission spectrometry). Electron microscopic X·ray microanalysis after chemical fixation showed little or no accumulation of Ti in the cells of the treated organs . However, if there was in appreciable Xray emission at 4.5 keV (Ti), it was recorded from the nucleoplasm and nucleolus. The comparison of ICPAES and X-ray analyses leads us to the conclusion that the majority of Ti may be in a diffusible form in the treated cells, except the nuclei, where Ti may be bound firmly
Overtone and multi-mode RR Lyrae stars in the globular cluster M3
The overtone and multi-mode RR Lyrae stars in the globular cluster M3 are
studied using a 200-d long, and time-series photometry
obtained in 2012. 70\% of the 52 overtone variables observed show some kind of
multi-periodicity (additional frequency at
frequency ratio, Blazhko effect, double/multi-mode pulsation, period doubling).
A signal at 0.587 frequency ratio to the fundamental-mode frequency is detected
in the double-mode star, V13, which may be identified as the second radial
overtone mode. If this mode-identification is correct, than V13 is the first RR
Lyrae star showing triple-mode pulsation of the first three radial modes.
Either the Blazhko effect or the frequency (or both of these
phenomena) appear in 7 double-mode stars. The
period ratio of RRd stars showing the Blazhko effect are anomalous. A
displacement of the main frequency component at the fundamental-mode with the
value of modulation frequency (or its half) is detected in three Blazhko RRd
stars parallel with the appearance of the overtone-mode pulsation. The
frequency appears in RRc stars that lie at the blue side of the
double-mode region and in RRd stars, raising the suspicion that its occurrence
may be connected to double-mode pulsation. The changes of the Blazhko and
double-mode properties of the stars are also reviewed using the recent and
archive photometric data.Comment: accepted for publication in ApJ Suppl. 26 pages, 25 figure
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