Stoichiometry and thermodynamics of the interaction between the C-terminus of human 90 kDa heat shock protein Hsp90 and the mitochondrial translocase of outer membrane Tom70

A large majority of the 1000-1500 proteins in the mitochondria are encoded by the nuclear genome, and therefore, they are translated in the cytosol in the form and contain signals to enable the import of proteins into the organelle. The TOM complex is the major translocase of the outer membrane responsible for preprotein translocation. It consists of a general import pore complex and two membrane import receptors, Tom20 and Tom70. Tom70 contains a characteristic TPR domain, which is a docking site for the Hsp70 and Hsp90 chaperones. These chaperones are involved in protecting cytosolic preproteins from aggregation and then in delivering them to the TOM complex. Although highly significant, many aspects of the interaction between Tom70 and Hsp90 are still uncertain. Thus, we used biophysical tools to study the interaction between the C-terminal domain of Hsp90 (C-Hsp90), which contains the EEVD motif that binds to TPR domains, and the cytosolic fragment of Tom70. The results indicate a stoichiometry of binding of one monomer of Tom70 per dimer of C-Hsp90 with a K(D) of 360 30 nM, and the stoichiometry and thermodynamic parameters obtained suggested that Tom70 presents a different mechanism of interaction with Hsp90 when compared with other TPR proteins investigated. (C) 2011 Elsevier Inc. All rights reserved.

Interaction of bovine serum albumin (BSA) with ionic surfactants evaluated by electron paramagnetic resonance (EPR) spectroscopy

EPR spectra of 5- and 16-doxyl stearic acid nitroxide probes (5-DSA and 16-DSA, respectively) bound to bovine serum albumin (BSA) revealed that in the presence of ionic surfactants, at least, two label populations coexist in equilibrium. The rotational correlation times (tau) indicated that component I displays a more restricted mobility state, associated to the spin labels bound to the protein; the less immobilized component 2 is due to label localization in the surfactant aggregates. For both probes, the increase of surfactant concentration leads to higher motional levels of component 1 followed by a simultaneous decrease of this fraction of nitroxides and its conversion into component 2. For 10 mM cethyltrimethylammonium chloride (CTAC), the nitroxides are 100% bound to the protein, whereas at 10mM N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (HPS) and sodium dodecyl sulfate (SDS) the fractions of bound nitroxides are reduced to 18% and 86%, respectively. No significant polarity changes were observed in the whole surfactant concentration range for component 1. Moreover, at higher surfactant concentration, component 2 exhibited a similar polarity as in the pure surfactant micelles. For 16-DSA the surfactant effect is different: at 10mM of HPS and CTAC the fractions of bound nitroxides are 76% and 49%, respectively, while at 10 mM SDS they are present exclusively in a micellar environment, consistent with 100% of component 2. Overall, both SDS and HPS are able to effectively displace the nitroxide probes from the protein binding sites. while CTAC seems to affect the nitroxide binding to a significantly smaller extent. (C) 2008 Elsevier B.V. All rights reserved.

The origin of the molecular interaction between amino acids and gold nanoparticles: A theoretical and experimental investigation

This study describes the synthesis of novel biological hybrid materials, where 3D structures were obtained using gold nanoparticles (AuNps) and methionine (Met) in a one-step procedure in aqueous media. The type of nanostructure can be controlled by tuning the intermolecular interactions between Met and AuNp, which strongly depends on the pH used for the synthesis. Computational simulation using the density-functional theory (DFT) showed that the AuNp - Met 3D structures are formed upon reorientation of Met molecules so that the backbone amine groups interact via H-bonds. These findings were experimentally confirmed using FTIR and UV-vis spectroscopy. Crown Copyright (C) 2008 Published by Elsevier B. V. All rights reserved.

A novel nanostructured composite formed by interaction of copper octa(3-aminopropyl)octasilsesquioxane with azide ligands: Preparation, characterization and a voltammetric application

This study presents the preparation, characterization and application of copper octa(3-aminopropyl)octasilsesquioxane following its subsequent reaction with azide ions (ASCA). The precursor (AC) and the novel compound (ASCA) were characterized by Fourier transform infrared spectra (FTIR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), scanning electronic microscopy (SEM), X-ray diffraction (XRD), Thermogravimetric analyses and voltammetric technique. The cyclic voltammogram of the modified graphite paste electrode with ASCA (GPE-ASCA), showed one redox couple with formal potential (E(1/2)(ox)) = 0.30 V and an irreversible process at 1.1 V (vs. Ag/AgCl; NaCl 1.0 M; v = 20 mV s(-1)). The material is very sensitive to nitrite concentrations. The modified graphite paste electrode (GPE-ASCA) gives a linear range from 1.0 x 10(-4) to 4.0 x 10(-3) mol L(-1) for the determination of nitrite, with a detection limit of 2.1 x 10(-4) mol L(-1) and the amperometric sensitivity of 8.04 mA/mol L(-1). (C) 2010 Elsevier Ltd. All rights reserved.

Removal of Zn(2+) from Electroplating Wastewater Using Modified Wood Sawdust and Sugarcane Bagasse

This paper describes the preparation of new adsorbents derived from sugarcane bagasse and wood sawdust (Manilkara sp.) to remove zinc (II) ions from electroplating wastewater. The first part deals with the chemical modification of sugarcane bagasse and wood sawdust, using succinic anhydride to introduce carboxylic acid functions into the material. The obtained materials (modified sugarcane bagasse MB2 and modified wood sawdust MS2) were then characterized by infrared spectroscopy (IR) and used in adsorption experiments. The adsorption experiments evaluates Zn(2+) removal from aqueous single metal solution and real electroplating wastewater on both batch and continuous experiments using fixed-bed columns prepared in laboratorial scale with the obtained adsorbents. Adsorption isotherms were then developed using Langmuir model and the Thomas kinetic model. The calculated Zn(2+) adsorption capacities were found to be 145 mg/g for MS2 and 125 mg/g for MB2 in single metal aqueous solution, whereas for the industrial wastewater these values were 61 mg/g for MS2 and 55 mg/g for MB2.

En studie av Idre Fjälls webbplats med fokus på användbarhet

Idre Fjäll currently has not full control of how visitors experience their site or if it has good usability. I have helped the company to do a usability test on their website to see how and where any improvements can be made on the page before the winter season 2010. I have also done a survey to investigate how users perceive Idre Fjälls website. Ten people of various ages participated in the survey. All test subjects was recorded with both audio and screen activity during the tests. The test consisted of five different tasks to be solved over the internet at Idre fjälls website. Nr 1, 3, 4 and 5 was solved for most without problem. In nr 2, where a booking of a house would be done, here arose a problem in nine tests out of ten. The results show that the site has very good graphic design and information design, but some weaknesses in interaction design. I have worked out proposals on the most significant problems identified during the test.

Personlighetstyper och upplevelse av ett nytt arbetsstöd : undersökning gjord på Trafikverkets Intranät och anställda

In order to get a better understanding of the interaction between employees and their technical work tools one needs to know what factors influence the interaction. The purpose of this study was to examine if there is a correlation between the personality traits Extraversion (E) and Neuroticism (N), tested with Eysenck Personality Inventory (EPI), and experience of the new Intranet among employees at The Swedish National Transport Administration (SNTA), and also to gather information of employees’ opinions about the new Intranet. A survey, containing questions about the Intranet and a personality test (EPI), was posted on SNTA’s Intranet for eight workdays (N = 88, females = 53, males = 35). A Multiple Regression showed no significant correlations between personality traits (E/N) and experience of the new Intranet. Considering the study’s low Power (.34) one cannot draw any conclusions of the statistical tests. A majority of the participants did not think that the new Intranet is better than the old one, and thought it was difficult to find necessary information on the Intranet at first. However, they did not think this had a negative effect on the time it took to accomplish their work tasks. For upcoming studies more participants are required (preferable more than 200) and the survey should not only be available via computers in order to reach people who is not frequent users of computers.

The concept of e-service from a social interaction perspective

Today’s e-services are complex phenomenon consisting of several different e-services linked together. The e-services are provided by IT systems and presented to customers through user interfaces. Within web design research criteria are laid out for the design of good user interfaces, but one problem is that these analyses are performed without a service focus. This lack of service focus can result in the designed user interfaces providing indistinct service concepts, especially where several e-services are intertwined with each other.In order to design IT system interfaces, we have to be clear about which e-services are provided by the IT system and how these e-services are related to each other. This paper presents a framework for the analysis of user interfaces in terms of focused e-service, service environment and two types of intertwined e-services; related e-services and interrelating e-services. The analyses are exemplified by an Internet based e-marketplace. The paper discusses how the framework can be combined with ordinary web design criteria and how it can be used for e-service development.

About Collaboration, Interaction, and the Negotiation of Meaning in Synchronous Written Chats in L2-German

Open Access

Perspektiv på ålder i vardagslivets interaktioner

Perspective on age in everyday interactions The aim of the article is to discuss how ethnomethodology and (symbolic) interactionism may contribute to sociological studies on age in everyday interactions. A theoretical framework on age, ‘age-as-accomplished’, inspired by ethnomethodology and symbolic interactionist approach has been proposed by Laz (1998; 2003). Our comparison of these approaches show, that the perspectives are incompatible, for example with regard to the definitions of culture, interaction and meaning. As such issues are not discussed by Laz, the theoretical framework is lacking in transparency and clarity. Ultimately the definition of ‘age as accomplished’ is not congruent with the notions of meaning and interpretation as used by Laz. In some respects the perspectives may though be complementary and valuable in age studies, for example the detailed study of situated norms in ethnomethodology, as well as some new developments within (symbolic) interactionist perspectives focusing on social status, and issues of subordination and superordination as relational processes.

Rule versus interaction function : evaluating regional aggregations of commuting flows in Sweden

The aim of this paper is to evaluate the performance of two divergent methods for delineating commuting regions, also called labour market areas, in a situation that the base spatial units differ largely in size as a result of an irregular population distribution. Commuting patterns in Sweden have been analyzed with geographical information system technology by delineating commuting regions using two regionalization methods. One, a rule-based method, uses one-way commuting flows to delineate local labour market areas in a top-down procedure based on the selection of predefined employment centres. The other method, the interaction-based Intramax analysis, uses two-way flows in a bottom-up procedure based on numerical taxonomy principles. A comparison of these methods will expose a number of strengths and weaknesses. For both methods, the same data source has been used. The performance of both methods has been evaluated for the country as a whole using resident employed population, self-containment levels and job ratios for criteria. A more detailed evaluation has been done in the Goteborg metropolitan area by comparing regional patterns with the commuting fields of a number of urban centres in this area. It is concluded that both methods could benefit from the inclusion of additional control measures to identify improper allocations of municipalities.

Ellipsis as a marker of interaction in spoken discourse

In this article, we discuss strategies for interaction in spoken discourse, focusing on ellipsis phenomena in English. The data comes from the VOICE corpus of English as a Lingua Franca, and we analyse education data in the form of seminar and workshop discussions, working group meetings, interviews and conversations. The functions ellipsis carries in the data are Intersubjectivity, where participants develop and maintain an understanding in discourse; Continuers, which are examples of back channel support; Correction, both self- and other-initiated; Repetition; and Comments, which are similar to Continuers but do not have a back channel support function. We see that the first of these, Intersubjectivity, is by far the most popular, followed by Repetitions and Comments. These results are explained as consequences of the nature of the texts themselves, as some are discussions of presentations and so can be expected to contain many Repetitions, for example. The speech event is also an important factor, as events with asymmetrical power relations like interviews do not contain so many Continuers. Our clear conclusion is that the use of ellipsis is a strong marker of interaction in spoken discourse.

Patienters upplevelser av att vårdas på en akutmottagning : -en litteraturöversikt

Bakgrund: Vårdpersonalen på en akutmottagning har stora krav på sig, ansvar för många patienter och måste fatta många egna beslut, ibland med mycket kort betänketid. Vårdpersonalen möter många olika patienter med olika problem och personligheter, och måste bemöta varje patient så att denne känner sig bekräftad och sedd. Syfte: Syftet med litteraturöversikten är att undersöka patienters upplevelse av att vårdas på en akutmottagning. Metod: Artiklar till arbetet har söks i olika databaser. Aktuella artiklar har lästs och relevanta fynd har markerats, för att analyseras och sammanställa ett resultat. Resultat: Analysen resulterade i tre underrubriker: Information, Bemötande och Vårdmiljö, med uppdelning av positiva och negativa upplevelser. Många patienter var nöjda med vården, men hade låga förväntningar från början. Patienterna har förstående för personalens tuffa arbetsmiljö, men önskade att få bättre information om väntetid och undersökningar. De tyckte att väntetiden var för lång, och kände sig ofta ensamma och övergivna. Slutsats: Mycket behöver förändras för att patienterna ska få en mer positiv upplevelse av akuten. Detta arbeta kan hjälpa till att belysa vilka punkter som vården måste arbeta extra mycket med för att patienterna ska känna sig trygga, exempelvis bättre information om väntetider och ett bemötande där sjusköterskan ser hela patienten.

Från ord till handling : En kvalitativ studie om värdegrund och socialt innehåll för äldre på särskilt boende

Socialstyrelsens brukarundersökning visar att äldre som bor på särskilt boende är mest missnöjda med de aktiviteter och den sociala samvaron som verksamheten erbjuder. Äldreomsorgen bygger på den nationella värdegrunden som innefattar att den äldre ska få leva ett värdigt liv och känna välbefinnande, men det är inte klart hur denna värdegrund påverkar personalens arbetssätt eller de sociala aktiviteter som erbjuds. Vår studie angriper denna fråga. Fem särskilda boenden var representerade både från kommunala och privata vårdgivare i två olika kommuner. Semistrukturerade intervjuer genomfördes med de särskilda boendes enhetschefer, som sedan transkriberades och tematiskt analyserades. Vårt resultat tyder på att den nationella värdegrunden inom äldreomsorgen tolkas olika på alla de särskilda boendena. Alla enhetschefer la stor vikt på personcentrerad vård, men trots det så erbjöd man liknade sociala aktiviteter ofta då som gruppaktivitet. Resultaten diskuterar vi med hänvisning till Aktivitetsteorin och Gerotranscendenceteorin.