23 research outputs found
Reform of the School System as an Anthropological Problem – An Example from the History Education
The article is a longitudinal review of experimental research of high didactic systems
effects in history teaching over the last 30 years. The aims of research are to evaluate: 1.
position of adolescent, especially neurotic pupils in the teaching process; 2. possibilities
to enhance the level of restructured matter (historical anthropology) in programmed
and problem-solving teaching; 3. influence on the anxiety, attitudes and success of pupils
with changes in the teaching process. Authors conclude, that the teaching process
can influence the emotional state of the neurotic pupil. Higher didactic systems in a
short time can influence the enhanced level of knowledge in relation to the traditional
teaching systems. In the new systems, the attitudes of the pupils towards the teaching
can change positively. Experiments carried out point to the possibility of changes of national
identity and the necessity of an anthropological approach to reform the educational
system
Trace-Element Concentrations In Human Hair Measured By Proton-Induced X-Ray Emission
Proton-induced x-ray spectroscopy has been used to measure trace element concentration ratios for 10 elements relative to Zn on a group of the population in the harbor city of Rijeka, Yugoslavia. The average biologic levels of elemental ratios for the inhabitants of this region have been established. The presence of pollutants has been confirmed by studying the variation of elemental concentration ratios along single samples of hair
He + clustering in Be
In a kinematically complete measurement of the
Li(Li,He)He reaction at = 8 MeV it was
observed that the Be excited states at 9.6 and 10.2 MeV decay by
He emission. The state at 10.2 MeV may be a member of a rotational band
based on the 6.18 MeV 0 state.Comment: 9 pages, RevTex, 3 Postscript figures (tarred, gzipped and uuencoded)
include
O-Glycosylation of snails
The glycosylation abilities of snails deserve attention, because snail species serve as intermediate hosts in the developmental cycles of some human and cattle parasites. In analogy to many other host-pathogen relations, the glycosylation of snail proteins may likewise contribute to these host-parasite interactions. Here we present an overview on the O-glycan structures of 8 different snails (land and water snails, with or without shell): Arion lusitanicus, Achatina fulica, Biomphalaria glabrata, Cepaea hortensis, Clea helena, Helix pomatia, Limax maximus and Planorbarius corneus. The O-glycans were released from the purified snail proteins by β-elimination. Further analysis was carried out by liquid chromatography coupled to electrospray ionization mass spectrometry and – for the main structures – by gas chromatography/mass spectrometry. Snail O-glycans are built from the four monosaccharide constituents: N-acetylgalactosamine, galactose, mannose and fucose. An additional modification is a methylation of the hexoses. The common trisaccharide core structure was determined in Arion lusitanicus to be N-acetylgalactosamine linked to the protein elongated by two 4-O-methylated galactose residues. Further elongations by methylated and unmethylated galactose and mannose residues and/or fucose are present. The typical snail O-glycan structures are different to those so far described. Similar to snail N-glycan structures they display methylated hexose residues
Insight into the Regulation of Glycan Synthesis in Drosophila Chaoptin Based on Mass Spectrometry
BACKGROUND: A variety of N-glycans attached to protein are known to involve in many important biological functions. Endoplasmic reticulum (ER) and Golgi localized enzymes are responsible to this template-independent glycan synthesis resulting glycoforms at each asparagine residues. The regulation mechanism such glycan synthesis remains largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: In order to investigate the relationship between glycan structure and protein conformation, we analyzed a glycoprotein of Drosophila melanogaster, chaoptin (Chp), which is localized in photoreceptor cells and is bound to the cell membrane via a glycosylphosphatidylinositol anchor. Detailed analysis based on mass spectrometry revealed the presence of 13 N-glycosylation sites and the composition of the glycoform at each site. The synthetic pathway of glycans was speculated from the observed glycan structures and the composition at each N-glycosylation site, where the presence of novel routes were suggested. The distribution of glycoforms on a Chp polypeptide suggested that various processing enzymes act on the exterior of Chp in the Golgi apparatus, although virtually no enzyme can gain access to the interior of the horseshoe-shaped scaffold, hence explaining the presence of longer glycans within the interior. Furthermore, analysis of Chp from a mutant (RNAi against dolichyl-phosphate alpha-d-mannosyltransferase), which affects N-glycan synthesis in the ER, revealed that truncated glycan structures were processed. As a result, the distribution of glycoforms was affected for the high-mannose-type glycans only, whereas other types of glycans remained similar to those observed in the control and wild-type. CONCLUSIONS/SIGNIFICANCE: These results indicate that glycan processing depends largely on the backbone structure of the parent polypeptide. The information we obtained can be applied to other members of the LRR family of proteins