Retrograde Transport from the Pre-Golgi Intermediate Compartment and the Golgi Complex Is Affected by the Vacuolar H+-ATPase Inhibitor Bafilomycin A1

The effect of the vacuolar H+-ATPase inhibitor bafilomycin A1 (Baf A1) on the localization of pre-Golgi intermediate compartment (IC) and Golgi marker proteins was used to study the role of acidification in the function of early secretory compartments. Baf A1 inhibited both brefeldin A- and nocodazole-induced retrograde transport of Golgi proteins to the endoplasmic reticulum (ER), whereas anterograde ER-to-Golgi transport remained largely unaffected. Furthermore, p58/ERGIC-53, which normally cycles between the ER, IC, and cis-Golgi, was arrested in pre-Golgi tubules and vacuoles, and the number of p58-positive ∼80-nm Golgi (coatomer protein I) vesicles was reduced, suggesting that the drug inhibits the retrieval of the protein from post-ER compartments. In parallel, redistribution of β-coatomer protein from the Golgi to peripheral pre-Golgi structures took place. The small GTPase rab1p was detected in short pre-Golgi tubules in control cells and was efficiently recruited to the tubules accumulating in the presence of Baf A1. In contrast, these tubules showed no enrichment of newly synthesized, anterogradely transported proteins, indicating that they participate in retrograde transport. These results suggest that the pre-Golgi structures contain an active H+-ATPase that regulates retrograde transport at the ER–Golgi boundary. Interestingly, although Baf A1 had distinct effects on peripheral pre-Golgi structures, only more central, p58-containing elements accumulated detectable amounts of 3-(2,4-dinitroanilino)-3′-amino-N-methyldipropylamine (DAMP), a marker for acidic compartments, raising the possibility that the lumenal pH of the pre-Golgi structures gradually changes in parallel with their translocation to the Golgi region.

Magnus den Godes, Harald Haardraades og hans sønners sagaer;

Mode of access: Internet.

Sustained neuronal activity generated by glial plasticity

Astrocytes release gliotransmitters, notably glutamate, that can affect neuronal and synaptic activity. In particular, astrocytic glutamate release results in the generation of NMDA receptor (NMDA-R)-mediated slow inward currents (SICs) in neurons. However, factors underlying the emergence of SICs and their physiological roles are essentially unknown. Here we show that, in acute slices of rat somatosensory thalamus, stimulation of lemniscal or cortical afferents results in a sustained increase of SICs in thalamocortical (TC) neurons that outlasts the duration of the stimulus by 1 h. This long-term enhancement of astrocytic glutamate release is induced by group I metabotropic glutamate receptors and is dependent on astrocytic intracellular calcium. Neuronal SICs are mediated by extrasynaptic NR2B subunit-containing NMDA-Rs and are capable of eliciting bursts. These are distinct from T-type Ca2+ channel-dependent bursts of action potentials and are synchronized in neighboring TC neurons. These findings describe a previously unrecognized form of excitatory, nonsynaptic plasticity in the CNS that feeds forward to generate local neuronal firing long after stimulus termination.

Nicotinic acetylcholine receptor interaction with β-amyloid:molecular, cellular, and physiological consequences

Elevated amyloid-β peptide (Aβ) and loss of nicotinic acetylcholine receptors (nAChRs) stand prominently in the etiology of Alzheimer's disease (AD). Since the discovery of an Aβ - nAChR interaction, much effort has been expended to characterize the consequences of high versus low concentrations of Aβ on nAChRs. This review will discuss current knowledge on the subject at the molecular, cellular, and physiological levels with particular emphasis on understanding how Aβ - nAChR interaction may contribute to normal physiological processes as well as the etiology of AD. ©2010 Bentham Science Publishers Ltd.

When an intercultural business negotiation fails:comparing the emotions and behavioural tendencies of individualistic and collectivistic negotiators

This study explores the linkages between culture, emotions and behavioural tendencies in unsuccessful intercultural business negotiations. A set of novel research hypotheses are developed. They are tested using a negotiation scenario analysis involving 106 Finnish and 114 Indian study participants. Three key findings emerge from the statistical tests conducted. First, new empirical evidence suggesting that qualitatively different emotions (dejection vs. agitation) are experienced after a failed intercultural business negotiation by individualists and collectivists is provided. Second, the existence of the relationship between perspective-taking ability and emotional volatility in the context of failed intercultural business negotiation involving individualists and collectivists is revealed. Third, partial support is found for the idea that different types of negative emotions can lead to the same behavioural tendency (approach) among individualists and collectivists when intercultural business negotiation fails. The paper concludes by outlining a set of theoretical and managerial implications and suggestions for further research.

Mixing performance evaluation of additive manufactured milli-scale reactors

The mixing performance of three passive milli-scale reactors with different geometries was investigated at different Reynolds numbers. The effects of design and operating characteristics such as mixing channel shape and volume flow rate were investigated. The main objective of this work was to demonstrate a process design method that uses on Computational Fluid Dynamics (CFD) for modeling and Additive Manufacturing (AM) technology for manufacture. The reactors were designed and simulated using SolidWorks and Fluent 15.0 software, respectively. Manufacturing of the devices was performed with an EOS M-series AM system. Step response experiments with distilled Millipore water and sodium hydroxide solution provided time-dependent concentration profiles. Villermaux-Dushman reaction experiments were also conducted for additional verification of CFD results and for mixing efficiency evaluation of the different geometries. Time-dependent concentration data and reaction evaluation showed that the performance of the AM-manufactured reactors matched the CFD results reasonably well. The proposed design method allows the implementation of new and innovative solutions, especially in the process design phase, for industrial scale reactor technologies. In addition, rapid implementation is another advantage due to the virtual flow design and due to the fast manufacturing which uses the same geometric file formats.

3D-grafiikan selaintekniikat, erikoistapauksena karttasovellukset

Harava on karttapohjainen kyselypalvelu, jonka avulla voidaan kerätä tietoa erilaisista kyselykohteista. Harava-kyselypalvelussa kyselyihin voidaan vastata muun muassa tekstikentillä, monivalinnoilla ja merkitsemällä alueita ja pisteitä karttapohjaan. Tutkielman tavoitteena oli löytää Harava-kyselypalvelun 2D-karttojen rinnalle 3D-karttavaihtoehto. Aluksi tutkittiin, mitä eri vaihtoehtoja löytyy 3D-komponenttien esittämiseen selaimessa. Tutkituista vaihtoehdoista parhaimmaksi tähän tarkoitukseen osoittautui WebGL-kirjasto. WebGL-kirjaston käyttö suoraan osoittautui vaikeaksi, joten etsittiin rajapintaa, jonka avulla WebGL-kirjaston käyttö helpottuisi. Käsittelyyn otettiin karttapalveluita sekä 3D-mallien esittämiseen tarkoitettuja JavaScript-kirjastoja, jotka käyttävät WebGL-kirjastoa rajapinnan kautta. Näistä sopivimmaksi osoittautui Cesium. Cesium on JavaScript-kirjasto, jonka avulla voidaan toteuttaa 2D-kartta ja 3D-karttapallo sekä upottaa karttapohjaan 3D-elementtejä.

Liquid-phase alcohol promoted methanol synthesis from CO2 and H2

Methanol is an important and versatile compound with various uses as a fuel and a feedstock chemical. Methanol is also a potential chemical energy carrier. Due to the fluctuating nature of renewable energy sources such as wind or solar, storage of energy is required to balance the varying supply and demand. Excess electrical energy generated at peak periods can be stored by using the energy in the production of chemical compounds. The conventional industrial production of methanol is based on the gas-phase synthesis from synthesis gas generated from fossil sources, primarily natural gas. Methanol can also be produced by hydrogenation of CO2. The production of methanol from CO2 captured from emission sources or even directly from the atmosphere would allow sustainable production based on a nearly limitless carbon source, while helping to reduce the increasing CO2 concentration in the atmosphere. Hydrogen for synthesis can be produced by electrolysis of water utilizing renewable electricity. A new liquid-phase methanol synthesis process has been proposed. In this process, a conventional methanol synthesis catalyst is mixed in suspension with a liquid alcohol solvent. The alcohol acts as a catalytic solvent by enabling a new reaction route, potentially allowing the synthesis of methanol at lower temperatures and pressures compared to conventional processes. For this thesis, the alcohol promoted liquid phase methanol synthesis process was tested at laboratory scale. Batch and semibatch reaction experiments were performed in an autoclave reactor, using a conventional Cu/ZnO catalyst and ethanol and 2-butanol as the alcoholic solvents. Experiments were performed at the pressure range of 30-60 bar and at temperatures of 160-200 °C. The productivity of methanol was found to increase with increasing pressure and temperature. In the studied process conditions a maximum volumetric productivity of 1.9 g of methanol per liter of solvent per hour was obtained, while the maximum catalyst specific productivity was found to be 40.2 g of methanol per kg of catalyst per hour. The productivity values are low compared to both industrial synthesis and to gas-phase synthesis from CO2. However, the reaction temperatures and pressures employed were lower compared to gas-phase processes. While the productivity is not high enough for large-scale industrial operation, the milder reaction conditions and simple operation could prove useful for small-scale operations. Finally, a preliminary design for an alcohol promoted, liquid-phase methanol synthesis process was created using the data obtained from the experiments. The demonstration scale process was scaled to an electrolyzer unit producing 1 Nm3 of hydrogen per hour. This Master’s thesis is closely connected to LUT REFLEX-platform.

Arvon erityispiirteistä asiakaspainotteisessa logiikassa: teoreettis-käsitteellinen tarkastelu

Asiakaspainotteinen logiikka on etenkin Heinosen ja Strandvikin kehittämä asiakaskeskeinen liiketoimintanäkökulma. Asiakaspainotteinen logiikka on kontribuutio hyödykepainotteista ja palvelupainotteista markkinointilogiikoita käsittelevään keskusteluun. Näkökulman asemointi omaksi erilliseksi markkinointilogiikaksi palvelupainotteisen ja hyödykepainotteisen logiikan rinnalle edellyttää logiikoiden arvokäsitysten vertailua. Arvon käsitettä lähestytään tutkielmassa Holbrookin (1999, 5) arvon määritelmää viitekehyksenä hyödyntäen. Viitekehyksessä arvon käsite jakaantuu arvon vuorovaikutteisuuteen, suhteellisuuteen ja kokemuksellisuuteen. Tämän tutkielman tarkoituksena on siten tarkastella arvon osatekijöitä asiakaspainotteisessa logiikassa. Tutkimusongelma jakaantuu kolmeen osaongelmaan. Ensimmäisessä osaongelmassa tutkitaan, mistä piirteistä arvon vuorovaikutteisuus koostuu asiakaspainotteisessa logiikassa. Toisessa osaongelmassa tutkitaan, mistä piirteistä arvon suhteellisuus koostuu asiakaspainotteisessa logiikassa. Kolmannessa osaongelmassa tutkitaan, mistä piirteistä arvon kokemuksellisuus koostuu asiakaspainotteisessa logiikassa. Teoriaosuudessa tarkastellaan markkinointilogiikan ja arvon käsitteitä. Markkinointilogiikoissa markkinoinnin arvokäsitteet yhdistetään taloustieteelliseen käsitteistöön. Osuudessa tarkasteltiin siten markkinoinnin ja taloustieteen arvoteoreettisia ja käsitteellisiä yhtymäkohtia. Hyödykepainotteisen ja palvelupainotteisen markkinointilogiikan arvoteoreettiset näkemykset analysoitiin Holbrookin (1999, 5) arvon määritelmästä muodostettua viitekehystä vasten. Tutkimus on luonteeltaan teoreettis-käsitteellinen tutkimus, jossa tieteellisistä artikkeleista koostuvaa aineistoa lähestytään tulkitsevasta näkökulmasta. Aineisto koostuu tutkielmassa kuudesta asiakaspainotteista logiikkaa koskevasta käsitteellisestä artikkelista tai kirjan luvusta. Tulkitsevassa aineiston analyysissä artikkelien arvoteoreettisia näkemyksiä tulkittiin tutkielmassa muodostettua viitekehystä vasten. Arvon vuorovaikutteisuus kohdistuu asiakaspainotteisessa logiikassa tarjoamasuhteeseen. Suhteellisuudella tarkoitetaan tarjoaman uppoutuneisuutta osaksi asiakkaan kokemusmaailmaa ja päätöksentekoprosesseja. Kokemuksellisuudella tarkoitetaan asiakaspainotteisessa logiikassa toiminnallista tärkeyttä eli tarjoaman asemaa asiakkaan päätöksenteossa.