3,034 research outputs found
Free dense subgroups of holomorphic automorphisms
We show the existence of free dense subgroups, generated by 2 elements, in
the holomorphic shear and overshear group of complex-Euklidean space and extend
this result to the group of holomorphic automorphisms of Stein manifolds with
Density Property, provided there exists a generalized translation. The
conjugation operator associated to this generalized translation is hypercyclic
on the topological space of holomorphic automorphisms.Comment: 9 page
QSO environments at intermediate redshifts
We have made a survey of quasar environments at 0.5 < z < 0.8, using a sample
of both radio-loud and radio-quiet quasars matched in B-band luminosity. Our
observations include images of background control fields to provide a good
determination of the field galaxy counts. About 10 per cent of the quasars
appear to live in rich clusters, whereas approximately 45 per cent live in
environments similar to that of field galaxies.
The richness of galaxies within a 0.5 Mpc radius around the radio-quiet
quasars is found to be indistinguishable from the richness around the
radio-loud quasars, corresponding on average to groups or poorer clusters of
galaxies. Comparing the galaxy richness in the radio-loud quasar fields with
quasar fields in the literature, we find no evidence of an evolution in the
environment with epoch. Instead, a weak, but significant correlation between
quasar radio luminosity and environmental richness is present. It is thus
possible that the environments of quasars, at least the powerful ones, do not
evolve much between the present epoch and z \approx 0.8.Comment: 6 pages, 4 figures, to appear in the proc. of the workshop `QSO hosts
and their environments', IAA, Granada 10-12 Jan, 200
Difficulties in Learning English As a Second Or Foreign Language
In this research project, the author explored the experience of one adult female immigrant to the United States and her difficulties in learning English as a second language (ESL) and identified several compounding reasons for her lack of expected progress. The research was accomplished by way of personal observation and interviews, which allowed the learner the opportunity to tell her own story in the phenomenological case study. There are many challenges that face foreign language (FL) learners and the learner struggled with notable difficulties. The findings showed that the learner, whose first and second languages were nonalphabetical, had never been taught the sound/letter rules system of English, and this fundamental deficit played a pivotal role in her poor classroom attendance, wavering motivation to learn and practice English, and ultimately, in her lack of progress. Implications included the need for basic sound/letter training to be implemented in basic ESL programs, especially for nonalphabetic first language learners
Introduction and Expression of a Rabbit β-globin Gene in Mouse Fibroblasts
The cloned chromosomal rabbit ß-globin gene has been introduced into mouse fibroblasts by DNA-mediated gene transfer (transformation). In this report, we examine the expression of the rabbit gene in six independent transformants that contain from 1 to 20 copies of the cloned globin gene. Rabbit globin transcripts were detected in two of these transformants at steady-state concentrations of 5 and 2 copies per cell. The globin transcripts from one cell line are polyadenylylated and migrate as 9S RNA on methylmercury gels. These transcripts reflect correct processing of the two intervening sequences but lack 48 ± 5 nucleotides present at the 5' terminus of rabbit erythrocyte globin mRNA
Radio-optical alignments in a low radio luminosity sample
We present an optically-based study of the alignment between the radio axes
and the optical major axes of eight z~0.7 radio galaxies in a 7C sample. The
radio galaxies in this sample are ~20-times less radio luminous than 3C
galaxies at the same redshift, and are significantly less radio-luminous than
any other well-defined samples studied to date. Using Nordic Optical Telescope
images taken in good seeing conditions at rest-frame wavelengths just longward
of the 4000A break, we find a statistically significant alignment effect in the
7C sample. Furthermore, in two cases where the aligned components are well
separated from the host we have been able to confirm spectroscopically that
they are indeed at the same redshift as the radio galaxy. However, a
quantitative analysis of the alignment in this sample and in a corresponding 3C
sample from HST archival data indicates that the percentage of aligned flux may
be lower and of smaller spatial scale in the 7C sample. Our study suggests that
alignments on the 50-kpc scale are probably closely related to the radio
luminosity, whereas those on the 15 kpc scale are not. We discuss these results
in the context of popular models for the alignment effect.Comment: 16 pages, 8 figures. Accepted by MNRA
Fruit quality in strawberry (Fragaria x ananassa Duch. cv. Korona) at three times during the season and with two fertilizer strategies
Effects on fruit quality of preplant fertilization and fertigation in strawberry were studied in a field experiment established August 2003 in South East Norway. Half the field was fertilized at planting and fertigated with a low nutrient rate from spring 2004 (T1), while the second half was unfertilized at planting but fertigated with a relatively high nutrient rate from spring 2004 (T2). Berries were harvested three times per week during the first harvesting year. Samples of berries from early season, mid season and late season were analysed for soluble solids, pH, titratable acidity, colour, vitamin C, antioxidant activity (FRAP) and mineral concentration. The results were correlated to leaf mineral concentration in dry matter. T1 gave larger and darker berries compared to T2. The other quality parameters and mineral content in strawberry fruits were not significantly influenced by the two fertilizer strategies. Soluble solids, pH, titratable acidity and colour varied significantly through the season, while vitamin C and antioxidant activity (FRAP) was unaffected by fertilizer treatment, berry size and time of season. The results gave a general view of the quality parameters in the strawberry cultivar ‘Korona’
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