Karyotype structure and chromosome fragility in the grass Phleum echinatum Host

Phleum echinatum Host (2n = 2x = 10) is an annual Mediterranean species which differs from other representatives of the genus Phleum by reduced chromosome number, asymmetric karyotype and unusually high amount of DNA in the genome. Chromosomes of this plant were studied using conventional acetic-orcein staining and fluorescence in situ hybridization (FISH). FISH showed the major 35S ribosomal DNA (rDNA) site at the secondary constriction of satellite chromosome (3) and the minor 35S rDNA site near 5S rDNA cluster in the monobrachial chromosome 5. Telomeric repeats were detected at all chromosome ends within secondary constriction in satellited chromosome 3 and at the centromeric regions of chromosomes 1 and 2. Intrachromosomally located telomeric repeats are probably traces of chromosomal rearrangements that have shaped P.echinatum genome; they were prone to breakage which was manifested in chromosome fragmentation. The most distinct telomeric signals, suggesting massive amplification of interstitial telomeric sequences (ITRs), were observed at the nucleolar organizer region (NOR) of the third chromosome pair. Double FISH confirmed co-localization of telomeric and 35S rDNA repeats in this locus characterized by the biggest fragility in the karyotype. Fragile sites of P.echinatum, composed of amplified telomeric repeats, may bear a resemblance to metazoan rare fragile sites enriched in microsatellite repeats

The Influence of Moderate Hypercapnia on Neural Activity in the Anesthetized Nonhuman Primate

Hypercapnia is often used as vasodilatory challenge in clinical applications and basic research. In functional magnetic resonance imaging (fMRI), elevated CO2 is applied to derive stimulus-induced changes in the cerebral rate of oxygen consumption (CMRO2) by measuring cerebral blood flow and blood-oxygenation-level–dependent (BOLD) signal. Such methods, however, assume that hypercapnia has no direct effect on CMRO2. In this study, we used combined intracortical recordings and fMRI in the visual cortex of anesthetized macaque monkeys to show that spontaneous neuronal activity is in fact significantly reduced by moderate hypercapnia. As expected, measurement of cerebral blood volume using an exogenous contrast agent and of BOLD signal showed that both are increased during hypercapnia. In contrast to this, spontaneous fluctuations of local field potentials in the beta and gamma frequency range as well as multiunit activity are reduced by ∼15% during inhalation of 6% CO2 (pCO2 = 56 mmHg). A strong tendency toward a reduction of neuronal activity was also found at CO2 inhalation of 3% (pCO2 = 45 mmHg). This suggests that CMRO2 might be reduced during hypercapnia and caution must be exercised when hypercapnia is applied to calibrate the BOLD signal

An evaluation of the summer aerospace institutes held at Northern Illinois University, 1959-1963

Includes bibliographical references (pages [49]-51)This study was an evaluation of the use experienced teachers had made of knowledge gained from the Aerospace Institute held at Northern Illinois University during the summer session in the years 1959 to 1963. A review of previous research and related literature indicated there is a definite need for aerospace education in our schools as an integrated part of the school curriculum. The data for the present study were obtained from questionnaires sent to all experienced teachers and administrators who participated in the Aerospace Institute offered by Northern Illinois University in the summers from 1959 to 1963. Analysis of the data obtained from questionnaires revealed. 1. The reasons given most frequently for enrolling in the course were: a. Special interest in the subject, b. Need for more knowledge in the field, c. Need for credits toward a degree, to meet board requirements, or for salary increment. 2. The majority of respondents felt the subject matter was well-balanced, and most indicated they have used it in their classes. 3. Most respondents have made use of the free material which were given out, but only few have used the free loan films. 4. All respondents thought the flight experiences and field trips were essential to the course. 5. Rated "most worthwhile" in the course were units on aviation or space, and the making of visual aids. 6. Many of the participants felt they now have a better understanding of technical developments in air and space, and their activities indicated they are continuing their interest in aerospace. 7. All participants indicated they have recommended the course to others; and they also thought an advanced course would have merit. 8. Over half of the respondents rated the Aerospace Institute as better than any other college course they had taken. Conclusions to this study seem to indicated that the participating teachers and administrators felt the Aerospace Institute had fulfilled its main objective of preparing them to teach aerospace concepts in their classrooms. Participation in the workshops had increased both knowledge and interest in the field of aerospace education.M.S. (Master of Science

Bolshevism, by an eye-witness from Wisconsin,

Mode of access: Internet

Kreativer Neustart im öffentlichen Rundfunk

KREATIVER NEUSTART IM ÖFFENTLICHEN RUNDFUNK Kreativer Neustart im öffentlichen Rundfunk / Elliesen-Kliefoth, Imke (Rights reserved) ( -