Kinetic studies on strawberry anthocyanin hydrolysis by a thermostable anthocyanin-β-glycosidase from Aspergillus niger

Several kinetic characteristics of a thermostable anthocyanin-β-glycosidase from Aspergillus niger have been evaluated. With strawberry anthocyanins as substrate, at pH optimum (4·0) and t = 30°C, K_m was found to be $\text{123 ± 4 μ}\text{m}$ and V_max, 1·16 ± 0·06 μmol min^?1mg^?1 protein. Temperature optimum was observed at about 68°C. The apparent energy of activation was calculated to be 11 ± 1 kcal/mol. The inhibitory effect of different sugars and sugar derivatives was examined. Glucono-deltalactone ($\text{K}{}_{\mathrm{<mtext>i</mtext>}}\text{= 2·3 ± 0·1 μ}\text{m}$), gluconic acid ($\text{K}{}_{\mathrm{<mtext>i</mtext>}}\text{= 82 ± 2 μ}\text{m}$) and glucose ($\text{K}{}_{\mathrm{<mtext>i</mtext>}}\text{= 1·3 ± 0·1}\text{m}\text{m}$) appeared to be competitive inhibitors of this enzyme.     

An architecture for a configurable mixed-signal device

The mixed-signal programmable system-on-chip (PSOC) architecture for high-volume low-cost applications is presented. Programmable analog, digital, and clocking circuits are combined with flash memory and a microcontroller to provide a platform for single-chip solutions for low-cost consumer applications. Both programmable analog and digital circuits are designed to support a moderate level of abstraction, balancing flexibility against cost and performance. A rough comparison of alternative approaches based on functionality and cost is presented.     

Evidence for McKusick''s hypothesis of deficient collagen cross-linking in patients with homocystinuria

Fractionation of the venom of the spider Phoneutria nigriventer revealed that it was a mixture of several neurotoxic peptides. The peptides so far characterized either inhibited or induced neurotransmitter release. These effects were mediated by Ca2+ channels or increasing Na+ permeability through voltage sensitive Na(+)-channels, respectively. The pooled toxic components (fraction P4) showed stimulatory effects on acetylcholine release from brain cortical slices. In addition, a component of the observed effects resembling that of alpha-latrotoxin was identified, which was characterized by the ability to provoke release of acetylcholine (ACh) at low temperature and in a manner independent of extracellular Ca2+ and of voltage sensitive Na(+)-channels.     

A theory of personalisation of appearance: quantitative evaluation of qualitatively derived data

Using qualitative data, Blom and Monk (2003) derived a theory of why people choose to personalise the appearance of their PCs and mobile phones. This paper describes some quantitative data that provide some support for, and some modifications to, the theory. Individuals having personal home pages were recruited to fill in a questionnaire that assesses dispositions to personalise and its effects. In addition the 82 home pages were inspected to assess the extent of personalisation. This correlated significantly with the dispositions 'Frequency of Use' and 'Knowledge of Personalisation'. The questionnaire items corresponding to effects were factor analysed. A four-factor solution suggested item groupings similar, but not identical, to those used in the theory. There are significant positive correlations between the extent of personalisation and cognitive effects and enduring emotional effects. The value of quantitative data for confirming and refining a qualitative theory is discussed.     

Storage life of frozen salmonoids Effect of light and packaging conditions on carotenoid oxidation and lipid oxidation

Summary The combined effect of oxygen transmission of packaging material and of exposure to light with different spectral distribution on the oxidative degradation of carotenoids and lipids in frozen salmonoids has been characterized in a storage experiment with steaks of rainbow trout. The degradation of the carotenoid astaxanthin, as followed by HPLC analysis and tristimulus colorimetric measurement, was sensitive to the radiant flux density of UV light and less sensitive to the oxygen transmission rate of the packaging material, in agreement with previous findings for photooxidation of carotenoids in food model systems. This is in contrast to the lipid oxidation, which was found to be dependent on the accessability of oxygen rather than on exposure to UV light. Formation of peroxides in the product culminated after 3 months of storage (up to 8.4 mEq kg^–1 oil), and preceded the formation of thiobarbituric-acid-reactive substances. The product in packaging material with a high oxygen transmission rate (60 cm³ m^–2 bar^–1 per 24 h) reached a level of approximately 5 mol malonaldhyde/kg^–1 product, when stored exposed to standard fluorescent light or fluorescent light with a high UV component. Rancid taste was not detected by sensory evaluation for any of the products after 6 months of storage, whereas a bitter taste was noted for the product exposed to UV light.

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Die Haltbarkeit von Lachsforellen Einfluß von Licht und Verpackung auf die Carotenoid- und Fettoxydation

Zusammenfassung Der kombinierte Effekt von Sauerstoffdurchgang durch Verpackungsmaterial und der Lichteinwirkung verschiedener spektraler Verteilung auf den oxidativen Abbau der Carotinoide und Fette in gefrorenen Lachsforellen wurde in einem Lagerungsversuch untersucht. Der Abbau des Carotenoids Astaxanthin wurde mit HPLC undTristimulus-Calorimetrie beobachtet, und war empfindlich gegenüber UV-Licht und weniger empfindlich gegenüber der Sauerstoffdurchlässigkeit der Verpackung, was mit früheren Ergebnissen für Photooxidation der Carotinoide in Modellsystemen übereinstimmt. Dies widerspricht der Fettoxidation, die mehr von Sauerstoffzugang abhängig ist als von der Entwicklung des UV-Lichtes. Die Bildung von Peroxiden des Produktes kuliminierte nach 3monatiger Lagerung (bis 8,4 meq/kg Öl) und ging der Bildung von Thiobarbitursäure-aktiven Substanzen voraus. Das Produkt im Material mit hohem Sauerstoffdurchgang (60 cm³ m^–2 bar^–1 pro 24 h), das bei normalen fluorescierendem Licht oder bei fluorescierendem Licht mit hohem UV-Anteil aufbewahrt wurde, erreichte einen TBS-Wert von ungefähr 5 mol Malonaldehyd/kg Fleisch. Ein ranziger Geschmack wurde durch sensorische Bewertung nach 6monatiger Lagerung nicht erkannt, wohl aber ein bitterer Geschmack bei dem UV-Licht ausgesetzten Proben.

     

Correct program parallelisations

International Journal on Software Tools for Technology Transfer - A commonly used approach to develop deterministic parallel programs is to augment a sequential program with compiler directives...     

From big smartphone data to worldwide research: The Mobile Data Challenge

This paper presents an overview of the Mobile Data Challenge (MDC), a large-scale research initiative aimed at generating innovations around smartphone-based research, as well as community-based evaluation of mobile data analysis methodologies. First, we review the Lausanne Data Collection Campaign (LDCC), an initiative to collect unique longitudinal smartphone dataset for the MDC. Then, we introduce the Open and Dedicated Tracks of the MDC, describe the specific datasets used in each of them, discuss the key design and implementation aspects introduced in order to generate privacy-preserving and scientifically relevant mobile data resources for wider use by the research community, and summarize the main research trends found among the 100+ challenge submissions. We finalize by discussing the main lessons learned from the participation of several hundred researchers worldwide in the MDC Tracks.     

Physiotherapists in ergonomics

Recently, physiotherapy students in Denmark have been spending part of their hospital training period in a factory environment, studying working postures and work methods. It is concluded that physiotherapists so trained can provide patients with a better service and treatment through their improved knowledge of the causes of illness.     

Behavior of Pt Atoms on Oxide Supports During Reduction Treatments at Elevated Temperatures,Characterized by Aberration Corrected Stem Imaging

Abstract  

Aberration-corrected scanning transmission electron microscopy at the sub-?ngstr?m resolution allows imaging the structure of catalytic materials at the single atom level and permits fundamental studies of the behavior of heavy metal catalytic species as a result of elevated temperature gas-treatments. The present study is aimed at understanding the development of clusters and nanoparticles of Pt on γ-alumina during reduction treatments of a pre-oxidized highly dispersed catalyst. A special built ex situ reactor and a specimen holder allowing cyclic anaerobic transfer between the reactor and microscope were used for the study. The number of atoms in a nascent cluster can be determined along with the general shape of the cluster. Reduction experiments without air exposure of the sample showed that although clusters are formed at 500 °C, many Pt atoms are not associated with the cluster and are still dispersed on the catalyst support. After a 700 °C reduction, all of the Pt atoms are associated with the clusters. Movement of the clusters on the catalyst support is different depending upon the catalyst support.