4,990 research outputs found
Quantitative mixing results and inner functions
19 pages, no figures.-- MSC2000 codes: 30D05, 30D50, 37A05, 37A25, 37F10, 28D05, 11K55.MR#: MR2262783 (2007j:37003)Zbl#: Zbl 1125.30019We study in this paper estimates on the size of the sets of points which are well approximated by orbits of other points under certain dynamical systems. We apply the results obtained to the particular case of the dynamical system generated by inner functions in the unit disk of the complex plane.D. Pestana was supported by Grants BFM2003-04780 and BFM-2003-06335-C03-02, Ministerio de Ciencia y TecnologÃa, Spain. J. L. Fernández and M. V. Melián were supported by Grant BFM2003-04780 from Ministerio de Ciencia y TecnologÃa, Spain.Publicad
Distortion of boundary sets under inner functions. II
33 pages, no figures.-- MSC2000 codes: 32A30, 30C85, 30D50.MR#: MR1379286 (97b:30035)Zbl#: Zbl 0847.32005We present a study of the metric transformation properties of inner functions of several complex variables. Along the way we obtain fractional dimensional ergodic properties of classical inner functions.Publicad
Complex noise in diffusion-limited reactions of replicating and competing species
We derive exact Langevin-type equations governing quasispecies dynamics. The
inherent multiplicative noise has both real and imaginary parts. The numerical
simulation of the underlying complex stochastic partial differential equations
is carried out employing the Cholesky decomposition for the noise covariance
matrix. This noise produces unavoidable spatio-temporal density fluctuations
about the mean field value. In two dimensions, the fluctuations are suppressed
only when the diffusion time scale is much smaller than the amplification time
scale for the master species.Comment: 10 pages, 2 composite figure
Pre-tertiary engagement with online learning : Exploring uses of online learning environments and digital technology for progression into and through Higher Education
This report outlines work undertaken by the Institute of Education to explore how pre-tertiary experiences of online learning influences students? successful transitions into and through Higher Education. The work was commissioned by Pamoja Education, and the studies that were undertaken focused on the experiences of students and staff taking part in Pamoja Education courses offered as part of the International Baccalaureate Diploma Programme. The work involved reviewing previous literature about the role of technology in preparing students for University study; undertaking a survey of International Baccalaureate students (including Pamoja Education alumni) to explore their experiences; interviewing Pamoja Education alumni as a way of explaining and elaborating these patterns of experience; and asking teachers to reflect on how they worked with learners to support them online. Each of these areas of work is reported in a separate section of this report
Remote brainstorming: Methodological interventions in designing from a distance
This paper examines the immediate effects of group methods in facilitating remote team collaboration. We recruited seven teams with prior experience working together. All teams completed two current, complex, and open-ended design challenges using remote tools. We examined design activities before and after teams were given a design method intervention. The interventions were a Brainstorming Method to promote divergent thinking and the Five-Whys method to promote analytical thinking. Using OpenFace, we observed changes in emotion by examining facial expressions. We found that the brainstorming intervention did not have a change in ideation performance and the problem analysis intervention had a decrease in ideation performance. Teams used digital media to facilitate communication but were constrained by the media\u27s tools. Our results can inform teams in organizations interested in promoting divergent thinking to not expect immediate improvements in ideation performance following the introduction of a design method. Future research is required to identify relevant abilities and social skills needed to facilitate remote ideation through design methods
Las colecciones de anortositas canadienses del Museu de Geologia de Barcelona y de la Facultat de Geologia de la Universitat de Barcelona
Este trabajo aporta algunas precisiones sobre el origen y caracterÃsticas petrográficas de las colecciones gemelas de rocas anortosÃticas canadienses del Museu de Geologia de Barcelona y la Facultat de Geologia de la Universitat de Barcelona, asà como sobre su idoneidad a efectos museÃsticos y didácticos.
Palabras clave: Canadá, Québec, Anortosita de Langelier, Anortosita de Lac de Saint-Jean, cantera de Alma, petrografia, meta-anortosita, didáctica, colecciones de anortositas, Museu de Geologia, Universitat, Barcelona.This work provides new insights on the origin and petrographic features of the twin collections of canadian anorthositic rocks from Museu de Geologia of Barcelona and Faculty of Geology of University of Barcelona, as well as some considerations on its interest as exhibition and didactic samples.
Key words: Canada, Québec, Langelier anorthosite, Lac de Saint-Jean anorthosite, Alma quarry petrography, meta-anorthosite, didactics, anorthosite collections, Museu de Geologia, Universitat, Barcelona.Este trabajo aporta algunas precisiones sobre el origen y caracterÃsticas petrográficas de las colecciones gemelas de rocas anortosÃticas canadienses del Museu de Geologia de Barcelona y la Facultat de Geologia de la Universitat de Barcelona, asà como sobre su idoneidad a efectos museÃsticos y didácticos.
Palabras clave: Canadá, Québec, Anortosita de Langelier, Anortosita de Lac de Saint-Jean, cantera de Alma, petrografia, meta-anortosita, didáctica, colecciones de anortositas, Museu de Geologia, Universitat, Barcelona
Anticipating food price crises by reservoir computing
Anticipating price crises in the market of agri-commodities is critical to guarantee both the sustainability of the food system and to ensure food security. However, this is not an easy task, since the problem implies analyzing small and very volatile time series, which are highly influenced by external factors. In this paper, we show that suitable reservoir computing algorithms can be developed that outperform traditional approaches, by reducing the Mean Absolute Error and, more importantly, increasing the Market Direction Accuracy. For this purpose, the applicability of five variants of such method to forecast this market is explored, and their performance evaluated by comparing the results with those obtained with the standard LSTM and SARIMA benchmarks. We conclude that decomposing the time series and modeling each component with a separate RC is essential to successfully anticipate price trends, and that this method works even in the complex changing temporal scenario of the Covid-19 pandemic, when part of the data were collectedThe project that gave rise to these results received the support of a fellowship from ‘‘la Caixa’’ Foundation (ID 100010434). The fellowship code is LCF/BQ/DR20/11790028. This work has also been partially supported by the Spanish Ministry of Science, Innovation and Universities, Gobierno de España, under Contract No. PID2021-122711NB-C21; and by DG of Research and Technological Innovation of the Community of Madrid (Spain) under Contract No. IND2022/TIC-2371
INTEGRAL timing and localization performance
In this letter we report on the accuracy of the attitude, misalignment, orbit
and time correlation which are used to perform scientific analyses of the
INTEGRAL data. The boresight attitude during science pointings has an accuracy
of 3 arcsec. At the center of the field, the misalignments have been calibrated
leading to a location accuracy of 4 to 40 arcsec for the different instruments.
The spacecraft position is known within 10 meters. The relative timing between
instruments could be reconstructed within 10 microsec and the absolute timing
within 40 microsec.Comment: 5 pages, 2 figures, accepted for publication in A+A letters, INTEGRAL
special issu
Potential role for clinical calibration to increase engagement with and application of home telemonitoring: a report from the HeartCycle programme
Aims: There is a need for alternative strategies that might avoid recurrent admissions in patients with heart failure. Home Telemonitoring (HTM) to monitor patient’s symptoms from a distance may be useful. This study attempts to assess changes in HTM vital signs in response to daily life activities (variations in medication, salt intake, exercise and stress) and to stablish which variations affect weight, blood pressure (BP) and heart rate (HR). Methods and results: We assessed 76 patients with heart failure (mean age 76 ± 10.8 years, 75% male, mainly in NYHA class II/III and from ischaemic etiology cause). Patients were given a calendar of interventions scheduling activities approximately twice-a-week before measuring their vital signs. Eating salty food or a large meal were the activities that had a significant impact on weight gain (+0.3 kg; p<0.001 and p=0.006, respectively). Exercise and skipping a dose of medication other than diuretics increased heart rate (+3 bpm, p=0.001 and almost +2 bpm, p=0.016, respectively). Conclusions: Our HTM system was able to detect small changes in vital signs related to these activities. Further studies should assess if providing such a schedule of activities might be useful for patient education and could improve long-term adherence to recommended lifestyle changes
Long-term preservation of freeze-dried rabbit sperm by adding rosmarinic acid and different chelating agents
Freeze-drying (FD) technique has been applied as an alternative technology to preserve gene resources to allow simple sperm preservation and shipment at 4 degrees C. Nevertheless, DNA sperm might be damaged by mechanical or oxidative stress throughout FD procedure. Therefore, suitable protection to maintain DNA integrity is required. The aim of this study was to determine the effect of rosmarinic acid (RA) as an antioxidant and two chelating agents (EGTA and EDTA) on the DNA integrity of freeze-dried rabbit sperm after storage of the samples at 4 degrees C and room temperature for 8 months. Rabbit sperm were freeze-dried in basic medium (10 mM Tris-HCl buffer and 50 mM NaCl) supplemented with 50 mM EGTA (1), 50 mM EGTA plus 105 mu M RA (2), 50 mM EDTA (3) or 50 mM EDTA plus 105 mu M RA (4). Semen samples were kept at 4 degrees C and room temperature during 8 months. After rehydration, DNA integrity was evaluated with Sperm Chromatin Dispersion test observing that DNA fragmentation was higher when semen samples were freeze-dried with EGTA (10.9%) than with EDTA (4.1%) (p < 0.01). Furthermore, RA acted better under adverse conditions and no significant differences were found in temperature storage. Summarizing, FD is a method that can allow simple gene resources preservation among 4 degrees C to 25 degrees C during 8 months and transportation without the need for liquid nitrogen or dry ice. EDTA chelating agent is the most suitable media for freeze-dried rabbit sperm and the addition of RA protects the DNA against the oxidative stress caused during FD procedure
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