960 resultados para Export Pah
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Abstract
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Arabidopsis thaliana PHO1 is primarily expressed in the root vascular cylinder and is involved in the transfer of inorganic phosphate (Pi) from roots to shoots. To analyze the role of PHO1 in transport of Pi, we have generated transgenic plants expressing PHO1 in ectopic A. thaliana tissues using an estradiol-inducible promoter. Leaves treated with estradiol showed strong PHO1 expression, leading to detectable accumulation of PHO1 protein. Estradiol-mediated induction of PHO1 in leaves from soil-grown plants, in leaves and roots of plants grown in liquid culture, or in leaf mesophyll protoplasts, was all accompanied by the specific release of Pi to the extracellular medium as early as 2-3 h after addition of estradiol. Net Pi export triggered by PHO1 induction was enhanced by high extracellular Pi and weakly inhibited by the proton-ionophore carbonyl cyanide m-chlorophenylhydrazone. Expression of a PHO1-GFP construct complementing the pho1 mutant revealed GFP expression in punctate structures in the pericycle cells but no fluorescence at the plasma membrane. When expressed in onion epidermal cells or in tobacco mesophyll cells, PHO1-GFP was associated with similar punctate structures that co-localized with the Golgi/trans-Golgi network and uncharacterized vesicles. However, PHO1-GFP could be partially relocated to the plasma membrane in leaves infiltrated with a high-phosphate solution. Together, these results show that PHO1 can trigger Pi export in ectopic plant cells, strongly indicating that PHO1 is itself a Pi exporter. Interestingly, PHO1-mediated Pi export was associated with its localization to the Golgi and trans-Golgi networks, revealing a role for these organelles in Pi transport.
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Mycelia have been recently shown to actively transport polycyclic aromatic hydrocarbons (PAH) in water-unsaturated soil over the range of centimeters, thereby efficiently mobilizing hydrophobic PAH beyond their purely diffusive transport in air and water. However, the question if mycelia-based PAH transport has an effect on PAH biodegradation was so far unsolved. To address this, we developed a laboratory model microcosm mimicking air-water interfaces in soil. Chemical analyses demonstrated transport of the PAH fluorene (FLU) by the mycelial oomycete Pythium ultimum that was grown along the air-water interfaces. Furthermore, degradation of mycelia-transported FLU by the bacterium Burkholderia sartisoli RP037-mChe was indicated. Since this organism expresses eGFP in response to a FLU flux to the cell, it was also as a bacterial reporter of FLU bioavailability in the vicinity of mycelia. Confocal laser scanning microscopy (CLSM) and image analyses revealed a significant increase of eGFP expression in the presence of P. ultimum compared to controls without mycelia or FLU. Hence, we could show that physically separated FLU becomes bioavailable to bacteria after transport by mycelia. Experiments with silicon coated glass fibers capturing mycelia-transported FLU guided us to propose a three-step mechanism of passive uptake, active transport and diffusion-driven release. These experiments were also used to evaluate the contributions of these individual steps to the overall mycelial FLU transport rate.
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Phosphate homeostasis in multicellular eukaryotes depends on both phosphate influx and efflux. The mammalian Xenotropic Polytropic Virus Receptor 1 (XPR1) shares homology to the Arabidopsis PHO1, a phosphate exporter expressed in roots. However, phosphate export activity of XPR1 has not yet been demonstrated in a heterologous system. Here, wedemonstrate that transient expression in tobacco leaves of XPR1-GFP leads to specific phosphate export. Like PHO1-GFP, XPR1-GFP is localized predominantly to the endomembrane system in tobacco cells. These results show that tobacco leaves are a good heterologous system to study the transport activity of members of the PHO1/XPR1 family.
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PAH (N-(4-aminobenzoyl)glycin) clearance measurements have been used for 50 years in clinical research for the determination of renal plasma flow. The quantitation of PAH in plasma or urine is generally performed by colorimetric method after diazotation reaction but the measurements must be corrected for the unspecific residual response observed in blank plasma. We have developed a HPLC method to specifically determine PAH and its metabolite NAc-PAH using a gradient elution ion-pair reversed-phase chromatography with UV detection at 273 and 265 nm, respectively. The separations were performed at room temperature on a ChromCart (125 mmx4 mm I.D.) Nucleosil 100-5 microm C18AB cartridge column, using a gradient elution of MeOH-buffer pH 3.9 1:99-->15:85 over 15 min. The pH 3.9 buffered aqueous solution consisted in a mixture of 375 ml sodium citrate-citric acid solution (21.01 g citric acid and 8.0 g NaOH per liter), added up with 2.7 ml H3PO4 85%, 1.0 g of sodium heptanesulfonate and completed ad 1000 ml with ultrapure water. The N-acetyltransferase activity does not seem to notably affect PAH clearances, although NAc-PAH represents 10.2+/-2.7% of PAH excreted unchanged in 12 healthy subjects. The performance of the HPLC and the colorimetric method have been compared using urine and plasma samples collected from healthy volunteers. Good correlations (r=0.94 and 0.97, for plasma and urine, respectively) are found between the results obtained with both techniques. However, the colorimetric method gives higher concentrations of PAH in urine and lower concentrations in plasma than those determined by HPLC. Hence, both renal (ClR) and systemic (Cls) clearances are systematically higher (35.1 and 17.8%, respectively) with the colorimetric method. The fraction of PAH excreted by the kidney ClR/ClS calculated from HPLC data (n=143) is, as expected, always <1 (mean=0.73+/-0.11), whereas the colorimetric method gives a mean extraction ratio of 0.87+/-0.13 implying some unphysiological values (>1). In conclusion, HPLC not only enables the simultaneous quantitation of PAH and NAc-PAH, but may also provide more accurate and precise PAH clearance measurements.
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The social saving literature has highlighted the indispensable role that railways played before 1914 in several Latin American export-oriented economies, such as Mexico, Brazil and Argentina. The article analyses the case of Uruguay, a country that, by 1914, had built one of the densest railway networks in Latin America. The article shows that, in contrast to what happened in other economies of the region, the resource saving effects of the Uruguayan railways during the first globalisation were tiny due to the small share that railway output accounted for within the country's gross domestic product (GDP). Three complementary reasons are suggested to explain that result, namely: the geographical structure of the country; its sectoral specialisation; and the small scale of the Uruguayan economy. Due to these three characteristics, Uruguay was unable to benefit from railways in the way that other export-oriented Latin American economies did during the first period of globalisation. This conclusion draws attention to the geographic-specific character of railway technology.
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The transcriptional corepressor SMRT controls neuronal responsiveness of several transcription factors and can regulate neuroprotective and neurogenic pathways. SMRT is a multi-domain protein that complexes with HDAC3 as well as being capable of interactions with HDACs 1, 4, 5 and 7. We previously showed that in rat cortical neurons, nuclear localisation of SMRT requires histone deacetylase activity: Inhibition of class I/II HDACs by treatment with trichostatin A (TSA) causes redistribution of SMRT to the cytoplasm, and potentiates the activation of SMRT-repressed nuclear receptors. Here we have sought to identify the HDAC(s) and region(s) of SMRT responsible for anchoring it in the nucleus under normal circumstances and for mediating nuclear export following HDAC inhibition. We show that in rat cortical neurons SMRT export can be triggered by treatment with the class I-preferring HDAC inhibitor valproate and the HDAC2/3-selective inhibitor apicidin, and by HDAC3 knockdown, implicating HDAC3 activity as being required to maintain SMRT in the nucleus. HDAC3 interaction with SMRT's deacetylation activation domain (DAD) is known to be important for activation of HDAC3 deacetylase function. Consistent with a role for HDAC3 activity in promoting SMRT nuclear localization, we found that inactivation of SMRT's DAD by deletion or point mutation triggered partial redistribution of SMRT to the cytoplasm. We also investigated whether other regions of SMRT were involved in mediating nuclear export following HDAC inhibition. TSA- and valproate-induced SMRT export was strongly impaired by deletion of its repression domain-4 (RD4). Furthermore, over-expression of a region of SMRT containing the RD4 region suppressed TSA-induced export of full-length SMRT. Collectively these data support a model whereby SMRT's RD4 region can recruit factors capable of mediating nuclear export of SMRT, but whose function and/or recruitment is suppressed by HDAC3 activity. Furthermore, they underline the fact that HDAC inhibitors can cause reorganization and redistribution of corepressor complexes.
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The Class IIa histone deacetylases (HDAC)4 and HDAC5 play a role in neuronal survival and behavioral adaptation in the CNS. Phosphorylation at 2/3 N-terminal sites promote their nuclear export. We investigated whether non-canonical signaling routes to Class IIa HDAC export exist because of their association with the co-repressor Silencing Mediator Of Retinoic And Thyroid Hormone Receptors (SMRT). We found that, while HDAC5 and HDAC4 mutants lacking their N-terminal phosphorylation sites (HDAC4(MUT), HDAC5(MUT)) are constitutively nuclear, co-expression with SMRT renders them exportable by signals that trigger SMRT export, such as synaptic activity, HDAC inhibition, and Brain Derived Neurotrophic Factor (BDNF) signaling. We found that SMRT's repression domain 3 (RD3) is critical for co-shuttling of HDAC5(MUT), consistent with the role for this domain in Class IIa HDAC association. In the context of BDNF signaling, we found that HDAC5(WT), which was more cytoplasmic than HDAC5(MUT), accumulated in the nucleus after BDNF treatment. However, co-expression of SMRT blocked BDNF-induced HDAC5(WT) import in a RD3-dependent manner. In effect, SMRT-mediated HDAC5(WT) export was opposing the BDNF-induced HDAC5 nuclear accumulation observed in SMRT's absence. Thus, SMRT's presence may render Class IIa HDACs exportable by a wider range of signals than those which simply
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Little research has been conducted to guide the management of marketing variables, such as pricing, in systems business context. Furthermore, given that international partnering has become a popular mode of operation for SMEs, the objective of the current thesis was to explore the scantly researched topic of managing the pricing of integrated solutions in an export partnership. Specifically, the thesis synthesizes literature findings from the three areas of export pricing, systems business, and export partnerships. The empirical section of the study consists of a qualitative single-case study of a Finnish systems integrator that has recently launched its export operations. Primary data was collected by conducting four interviews of the case company’s managers and by organizing one group interview session. The study findings indicate that a systems integrator’s pricing strategy in an export partnership can be very multidimensional and dependant on international pricing environment and partner characteristics, that an export partnership appears to have unique implications on a systems integrator’s pricing process, and that customer value –based pricing strategies might be particularly suited to pricing integrated solutions.
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Public organizations form a significant part of any economy, yet their buying behavior has received very little attention. Operating with complex public sector is further complicated when sales and marketing activities are done by foreign export partners. This thesis explores the buying behavior of public organizations and how partnership governance is influenced by it. The theoretical part focuses on two subjects. Firstly the strictly regulated purchase process, rigid decision making and other special characteristics of public organizations are examined. Secondly the thesis examines partnership governance forms and how coordination is arranged in the relationships. The empirical part investigates the subjects of public organization buying behavior and partnership governance using a case study of a Finnish SME and their two export partners. The findings suggest high degree of uniformity between public organizations enables the use of unilateral governance forms. By creating mutual dependence through training the possibility of adopting a purely bilateral governance form exists as well.
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Tässä työssä selvitettiin altistutaanko kreosoottikyllästetyn puun käsittelyssä polysyklisille aromaattisille hiilivedyille ja mistä työsuojelullisista syistä altistumista tapahtuu. Lisäksi työssä selvitettiin mitä altistuminen tarkoittaa työnantajan kannalta. Altistumista tarkasteltiin työturvallisuuden näkökulmasta. Lähtöaineisto koostui maastossa toteutetuista tutkimuksista. Aineisto kerättiin kesällä 2009 kolmesta Itä-Suomessa sijaitsevasta kohteesta, joissa käsiteltiin kreosootilla kyllästettyä puuta. Altistumisen todentamiseksi tutkimukseen osallistuneilta työntekijöiltä pyydettiin virtsanäytteet, joista analysoitiin yhden yleisimmän PAH-altistumista indikoivan merkkiaineen, virtsan 1-pyrenolin pitoisuuksia työntekijöillä. Altistumisen syiden selvittämiseksi työntekijöitä haastateltiin ja havainnoitiin. Tulosten perusteella työntekijät altistuvat PAH-yhdisteille työssään. PAH-altistumisen merkkiaineena olleelle virtsan 1-pyrenolille ei toimenpiderajaa tällä hetkellä ole, mutta se on Työterveyslaitoksella suunnitteilla. Lainsäädäntö velvoittaa erinäisin toimenpitein työnantajaa minimoimaan työntekijöiden altistumisen syöpäsairauden vaaraa aiheuttaville aineille, kuten PAH-yhdisteille. Tulosten perusteella työsuojelutoimenpiteitä on syytä tehostaa altistumisen minimoimiseksi ja etenkin ihon suojaamiseen on syytä kiinnittää erityistä huomiota.
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Knowledge transfer is a complex process. Knowledge transfer in the form of exporting education products from one system of education to another is particularly complicated, because each system has been developed in a particular context to meet the requirements seen as relevant at each time. National innovation systems are often seen to form an essential framework within which the development of a country, its economy and level of knowledge are considered and promoted. These systems are orientated towards the future, and as such they also provide a framework for the knowledge transfer related to the development of education. In the best of circumstances they are able to facilitate and boost this transfer both from the viewpoint of the provider and the recipient. The leading thought and the idea of the study is that education export is a form of knowledge transfer, which is illustrated by the existing models included. The purpose of this study is to explore, analyze and describe the factors and phenomena related to education export, and more specifically, those related to the experiences and potential of Finnish education export to Chile. For better understanding, of the multiplicity of the issue involved, the current status of education export between Finland and Chile and he existing efforts within the Finnish innovation network will be outlined as well as new forms of co-operation between Finland and Chile in educational matters explored. Several countries have started to commercialize their education system in order to establish themselves as emerging education exporters. Moreover, the demand for education reform is accurate in many developing countries. This offers a good match between Finland and Chile to be the example countries of the research. The main research findings suggest that there are several business areas in education export. These include degrees in education, training services and education technologies for example The factors that influence education export can be divided into four groups, including academic, cultural, political and economic aspects. Challenges to overcome include the lack of product or services to be sold, lack of market and cultural knowledge of the buyer country, financing and lack of suitable pricing model. National innovation systems could be seen as enabling entities for successful education export. The extensive networks that national innovation systems aim to form, could operate as a basis for joining the forces in selling knowledge as well as receiving knowledge in a constructive way.
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After the economic reform, China has undergone fast economic growth, urbanization and adopted the western lifestyle. Global enterprises are investing in China and Finnish companies began to enter the Chinese market after the 1980s. Fast economic growth has downside effects like pollution and thus more cleantech solutions are needed. There are different kinds of entry modes that companies are using when entering the Chinese market. This thesis focuses on export tire entry mode. The purpose of this study is to examine cleantech companies’ opinions about the export tire operations. The background of this study is built by combining the written knowledge about the history of the Chinese industry and market entry modes. The empirical part of the study is a semi-structured, qualitative analysis of five case companies that are operating together in a particular export tire and represent the highest Finnish cleantech knowledge. The results of this study indicate that the export tire entry is an easy and cost effective way to enter new markets or market segment. Export tire is really dependent on the leader who in this particular case succeeded well.
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This thesis is based on studying integration synergies in a merger or acquisition situation with the interest in distribution channel integration. M&As seem to be forever popular and nowadays companies often use them as a certain kind of strategy to develop their business. M&As have attracted research for decades and also distribution in M&As has been found interesting. Moreover, research often concentrates to the horizontal M&A´s potential synergies that emerge in the integration process and so is the case also in this study as the core issue is to study the integration of the distribution channels and its potential synergies. This study concentrates on a single case, an acquisition which took place in 2011. The case consists of two Finnish companies operating in the same business field. Both of the companies are very export orientated, which gives this study its export view. As the companies operate in the same field this acquisition falls into the categorization of horizontal acquisition. The objective of the thesis is to study how the export channels could be integrated after an acquisition? This research question is divided again to three sub-questions asking how the distribution channels of the acquirer and acquired company are organized, what is pursued by the post-acquisition distribution channel integration and what are the integration challenges especially from the logistics point-of-view. The framework was built from the basis of the literature used in this thesis. The framework combines M&A process and distribution channels to a one united model which presents the progress of this thesis. The study was carried out as a qualitative research and as a holistic single case study. The data used in the research includes two interviews, other material from the case companies and also material of the companies collected by the author independently from different sources. There were many motives for the acquisition as usual. From the research results one can find that the integration process is still very ongoing and the synergies have not yet been fully discovered but also they are there to be found. The concentration of the research was in the export distribution which proved to be meaningful since the exports markets of the case companies were found to be quite complementary. The research results brought up also other issues concerning the post-acquisition integration process rather than the distribution channels and export. M&As are always a risky business. The final result can never be predicted. No matter how good the merging companies look on paper the practice is not the same. The acquisition process of this case has not ended yet and there lies potential synergy benefits to be discovered if enough effort is used to go through the process right.