Molecular mimicry in the recognition of glycosphingolipids by Gal{alpha}3Gal{beta}4GlcNAc{beta}-binding Clostridium difficile toxin A, human natural anti {alpha}-galactosyl IgG and the monoclonal antibody Gal-13: characterization of a binding-active human glycosphingolipid, non-identical with the animal receptor

Glycoconjugates with terminal Gal     

Do ringing numbers reflect true migratory activity of nocturnal migrants?

Summary In autumn 1998, nocturnal bird migration at Falsterbo was recorded over a period of three months by means of a passive infrared device. At the same place a standardised trapping scheme is in operation. This study reveals for the first time a positive correlation between the migratory intensity of birds aloft and the numbers of trapped birds. By relating the migratory patterns of single species with the nocturnal migratory intensities, we show that the species composition aloft can at least partly be deduced from the number of grounded birds. The numbers of trapped pre-Saharan migrants were related more strongly to the migratory intensity of the preceding night than were the numbers of trans-Saharan migrants. Assuming that the number of trapped birds varies according to the weather to the same extent as the migratory intensity of birds aloft, we conclude that in shorter range migrants the decision to engage in a migratory flight is influenced more strongly by weather conditions, and that the migratory activity of trans-Saharan migrants is possibly more intensely controlled by their endogenous migratory urge.

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Widerspiegeln Fangzahlen die tatsächlichen nächtlichen Zugdichten?

Zusammenfassung Fangzahlen aus der Vogelberingung werden Studien verschiedenster Gebiete der Ornithologie zu Grunde gelegt. Insbesondere in der Vogelzugforschung und in Populationsanalysen wurden dadurch grosse Fortschritte erzielt. In dieser Arbeit wird erstmals untersucht, inwiefern die Fangzahlen mit dem nächtlichen Zuggeschehen in Verbindung stehen. In Falsterbo, Südwest-Schweden, werden seit 20 Jahren Vögel in einem standardisierten Verfahren mit Japannetzen gefangen. Im Herbst 1998 beobachteten wir am gleichen Ort während drei Monaten den nächtlichen Vogelzug mittels einer Wärmebildkamera, wobei Singvögel bis maximal 3000 m über Boden erfasst werden. In 63 Fällen konnten wir die täglichen Fangzahlen mit den Zugintensitäten der vorangegangenen Nacht vergleichen, wobei wir eine signifikante positive Korrelation feststellten. Dabei mag die Lage der Fangstation an der Küste eine Rolle spielen, indem hier täglich ein bestimmter Anteil der Zugvögel eine Rast einlegt, bevor der Überflug der Ostsee bewältigt wird, während gleichzeitig kaum nicht-ziehende Vögel vorhanden sind. Der Vergleich der Zugmuster der 12 am häufigsten gefangenen Arten zeigt, dass die Anzahlen der Kurzstreckenzieher besser mit den nächtlichen Zugintensitäten übereinstimmen. Unter der Annahme, dass die Fangzahlen in gleichem Masse vom Wetter abhängen, wie dies für die Intensität des nächtlichen Zuges gezeigt werden konnte, schliessen wir auf eine deutliche Reaktion der Kurzstreckenzieher gegenüber dem Wetter. Im Gegensatz dazu scheint der Zug der Langstreckenzieher stärker von weiteren Faktoren beeinflusst, beispielsweise von der inneren Uhr. Möglicherweise bedeutet die Ostsee hinsichtlich ihrer weiten Reise ein unbedeutenderes Hindernis als für Arten, welche nur bis Mittel- oder Südeuropa ziehen. In der Folge neigen Kurzstreckenzieher wohl eher dazu an der Küste zu landen als Langstreckenzieher.

     

Half-site reactivity of the tyrosyl radical of ribonucleotide reductase from Escherichia coli

A C-terminally truncated form of protein B2, the homodimeric small subunit of ribonucleotide reductase from Escherichia coli, was found as the result of an apparently specific proteolysis. Truncated homodimers contain an intact binuclear iron center and a normal tyrosyl radical but have no binding capacity for the other ribonucleotide reductase subunit, protein B1, and are consequently enzymatically inactive. Heterodimers, consisting of one full-length and one truncated polypeptide, formed spontaneously during a chelation-reconstitution cycle and were easily separated from the two homodimeric variants. The heterodimeric form of B2 shows a weak interaction with the B1 subunit resulting in low enzyme activity. Using heterodimers containing deuterated tyrosine on the full-length side and protonated tyrosine on the truncated side, we could demonstrate that the tyrosyl radical was randomly generated in one or the other of the two polypeptide chains of the heterodimeric B2 subunit. The small subunit of ribonucleotide reductase thus conforms to a half-site reactivity.     

Dietary Intake in Relation to Restrained Eating,Disinhibition, and Hunger in Obese and Nonobese Swedish Women

The aims of this study were to: describe dietary intakes of obese and nonobese middle-aged women using a validated food frequency questionnaire; to assess dietary restraint, disinhibition, and hunger by the three factor eating questionnaire (TFEQ) in obese and nonobese samples and determine which of the factors are independently associated with obesity; and to examine correlations between selected nutritional variables and the TFEQ factors. Subjects studied included 179 obese Swedish women (BMI>32) and 147 nonobese population-based controls (BMI<28). Age-adjusted mean energy intake was significantly higher in obese women (2730 ± 78 vs. 2025 ± 85 kcal, p<0.0001). In absolute and relative terms, fat intake was higher and alcohol intake was lower in the obese subjects. Disinhibition was the strongest TFEQ factor independently differentiating the obese and nonobese states, i.e., after adjustment for restraint and hunger. Within the obese sample, strong associations were seen between energy intake and disinhibition (p=0.0005) and hunger (p=0.0004). The association between energy intake and restrained eating was negative and weaker (p=0.04). No such associations were seen in nonobese women. Thus, using a dietary instrument that is valid and unbiased with respect to obesity, strong psychological correlates, possibly causal, of variability in energy intake were detected in middle-aged women with obesity. Disinhibition is associated with both obesity and high-energy intakes and is therefore an important factor to consider in the treatment of women with obesity.     

Comparing the Performance of NoSQL Approaches for Managing Archetype-Based Electronic Health Record Data

This study provides an experimental performance evaluation on population-based queries of NoSQL databases storing archetype-based Electronic Health Record (EHR) data. There are few published studies regarding the performance of persistence mechanisms for systems that use multilevel modelling approaches, especially when the focus is on population-based queries. A healthcare dataset with 4.2 million records stored in a relational database (MySQL) was used to generate XML and JSON documents based on the openEHR reference model. Six datasets with different sizes were created from these documents and imported into three single machine XML databases (BaseX, eXistdb and Berkeley DB XML) and into a distributed NoSQL database system based on the MapReduce approach, Couchbase, deployed in different cluster configurations of 1, 2, 4, 8 and 12 machines. Population-based queries were submitted to those databases and to the original relational database. Database size and query response times are presented. The XML databases were considerably slower and required much more space than Couchbase. Overall, Couchbase had better response times than MySQL, especially for larger datasets. However, Couchbase requires indexing for each differently formulated query and the indexing time increases with the size of the datasets. The performances of the clusters with 2, 4, 8 and 12 nodes were not better than the single node cluster in relation to the query response time, but the indexing time was reduced proportionally to the number of nodes. The tested XML databases had acceptable performance for openEHR-based data in some querying use cases and small datasets, but were generally much slower than Couchbase. Couchbase also outperformed the response times of the relational database, but required more disk space and had a much longer indexing time. Systems like Couchbase are thus interesting research targets for scalable storage and querying of archetype-based EHR data when population-based use cases are of interest.     

Pyrazole-based arylalkyne cathepsin S inhibitors. Part II: Optimization of cellular potency

Basic lipophilic substituents dramatically improved the cellular potency of a previously disclosed series of pyrazole-based arylalkyne cathepsin S inhibitors. The incorporation of substituted benzylamines in the para position of the arylalkyne maintained enzymatic activity (hCatS IC₅₀ = 80–420 nM) and imparted cellular potency (IC₅₀ = 0.8–4.0 μM). Further refinement of the morpholine portion of the pharmacophore enabled the identification of bicyclic piperidines with enhanced affinity for CatS (IC₅₀ = 10–30 nM) and sub-micromolar cellular potency (JY Ii IC₅₀ = 200–720 nM).