895 resultados para Two operation modes
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The distinction between physiological (apoptotic) and pathological (necrotic) cell deaths reflects mechanistic differences in cellular disintegration and is of functional significance with respect to the outcomes that are triggered by the cell corpses. Mechanistically, apoptotic cells die via an active and ordered pathway; necrotic deaths, conversely, are chaotic and passive. Macrophages and other phagocytic cells recognize and engulf these dead cells. This clearance is believed to reveal an innate immunity, associated with inflammation in cases of pathological but not physiological cell deaths. Using objective and quantitative measures to assess these processes, we find that macrophages bind and engulf native apoptotic and necrotic cells to similar extents and with similar kinetics. However, recognition of these two classes of dying cells occurs via distinct and noncompeting mechanisms. Phosphatidylserine, which is externalized on both apoptotic and necrotic cells, is not a specific ligand for the recognition of either one. The distinct modes of recognition for these different corpses are linked to opposing responses from engulfing macrophages. Necrotic cells, when recognized, enhance proinflammatory responses of activated macrophages, although they are not sufficient to trigger macrophage activation. In marked contrast, apoptotic cells profoundly inhibit phlogistic macrophage responses; this represents a cell-associated, dominant-acting anti-inflammatory signaling activity acquired posttranslationally during the process of physiological cell death.
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We present the results of two-pump and probe femtosecond experiments designed to follow the relaxation dynamics of the lowest excited state (S1) populated by different modes. In the first mode, a direct (S0 → S1) radiative excitation of the ground state is used. In the second mode, an indirect excitation is used where the S1 state is populated by the use of two femtosecond laser pulses with different colors and delay times between them. The first pulse excites the S0 → S1 transition whereas the second pulse excites the S1 → Sn transition. The nonradiative relaxation from the Sn state populates the lowest excited state. Our results suggest that the S1 state relaxes faster when populated nonradiatively from the Sn state than when pumped directly by the S0 → S1 excitation. Additionally, the Sn → S1 nonradiative relaxation time is found to change by varying the delay time between the two pump pulses. The observed dependence of the lowest excited state population as well as its dependence on the delay between the two pump pulses are found to fit a kinetic model in which the Sn state populates a different surface (called S′1) than the one being directly excited (S1). The possible involvement of the Ag type states, the J intermediate, and the conical intersection leading to the S0 or to the isomerization product (K intermediate) are discussed in the framework of the proposed model.
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Kinetochores are DNA-protein structures that assemble on centromeric DNA and attach chromosomes to spindle microtubules. Because of their simplicity, the 125-bp centromeres of Saccharomyces cerevisiae are particularly amenable to molecular analysis. Budding yeast centromeres contain three sequence elements of which centromere DNA sequence element III (CDEIII) appears to be particularly important. cis-acting mutations in CDEIII and trans-acting mutations in genes encoding subunits of the CDEIII-binding complex (CBF3) prevent correct chromosome transmission. Using temperature-sensitive mutations in CBF3 subunits, we show a strong correlation between DNA-binding activity measured in vitro and kinetochore activity in vivo. We extend previous findings by Goh and Kilmartin [Goh, P.-Y. & Kilmartin, J.V. (1993) J. Cell Biol. 121, 503-512] to argue that DNA-bound CBF3 may be involved in the operation of a mitotic checkpoint but that functional CBF3 is not required for the assembly of a bipolar spindle.
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We describe a complete gene family encoding phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) in one particular plant species. In parsley (Petroselinum crispum), the PAL gene family comprises two closely related members, PAL1 and PAL2, whose TATA-proximal promoter and coding regions are almost identical, and two additional members, PAL3 and PAL4, with less similarity to one another and to the PAL1 and PAL2 genes. Using gene-specific probes derived from the 5' untranslated regions of PAL1/2, PAL3, and PAL4, we determined the respective mRNA levels in parsley leaves and cell cultures treated with UV light or fungal elicitor and in wounded leaves and roots. For comparison, the functionally closely related cinnamate 4-hydroxylase (C4H) and 4-coumarate:CoA ligase (4CL) mRNAs were measured in parallel. The results indicate various degrees of differential responsiveness of PAL4 relative to the other PAL gene family members, in contrast to a high degree of coordination in the overall expression of the PAL, C4H, and 4CL genes. The only significant sequence similarities shared by all four PAL gene promoters are a TATA-proximal set of three putative cis-acting elements (boxes P, A, and L). None of these elements alone, or the promoter region containing all of them together, conferred elicitor or light responsiveness on a reporter gene in transient expression assays. The elements appear to be necessary but not sufficient for elicitor- or light-mediated PAL gene activation, similar to the situation previously reported for 4CL.
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Although initially conceived as providing simply the preventive portion of an extended continuum of care for veterans, the Driving Under the Influence (DUI) program has turned out to be an important outreach service for active duty or recently discharged OEF/OIF (Operation Enduring Freedom/Operation Iraqi Freedom) veterans. Veterans receive empirically-based, state-mandated education and therapy under the only Department of Veterans Affairs (VA) - sponsored DUI program in the State of Colorado, with the advantage of having providers who are sensitive to symptoms of Post-Traumatic Stress Disorder (PTSD) and other relevant diagnoses specific to this population, including Traumatic Brain Injury (TBI). In this paper, the rapid growth of this program is described, as well as summary data regarding the completion, discontinuation, and augmentation of services from the original referral concern. Key results indicated that for nearly one third (31.9%) of the OEF/OIF veterans who were enrolled in the DUI program, this was their initial contact with the VA health care system. Furthermore, following their enrollment in the DUI program, more than one fourth (27.6%) were later referred to and attended other VA programs including PTSD rehabilitation and group therapy, anger management, and intensive inpatient or outpatient dual diagnosis programs. These and other findings from this study suggest that the DUI program may be an effective additional pathway for providing treatment that is particularly salient to the distinctive OEF/OIF population; one that may also result in earlier intervention for problem drinking and other problems related to combat. Relevant conclusions discussed herein primarily aim to improve providers' understanding of effective outreach, and to enhance the appropriate linkages between OEF/OIF veterans and existing VA services.
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Chandra data in the COSMOS, AEGIS-XD and 4 Ms Chandra Deep Field South are combined with multiwavelength photometry available in those fields to determine the rest-frame U − V versus V − J colours of X-ray AGN hosts in the redshift intervals 0.1 < z < 0.6 (mean z¯=0.40) and 0.6 < z < 1.2 (mean z¯=0.85). This combination of colours provides an effective and least model-dependent means of separating quiescent from star-forming, including dust reddened, galaxies. Morphological information emphasizes differences between AGN populations split by their U − V versus V − J colours. AGN in quiescent galaxies consist almost exclusively of bulges, while star-forming hosts are equally split between early- and late-type hosts. The position of AGN hosts on the U − V versusV − J diagram is then used to set limits on the accretion density of the Universe associated with evolved and star-forming systems independent of dust induced biases. It is found that most of the black hole growth at z≈ 0.40 and 0.85 is associated with star-forming hosts. Nevertheless, a non-negligible fraction of the X-ray luminosity density, about 15–20 per cent, at both z¯=0.40 and 0.85, is taking place in galaxies in the quiescent region of the U − V versus V − J diagram. For the low-redshift sub-sample, 0.1 < z < 0.6, we also find tentative evidence, significant at the 2σ level, that AGN split by their U − V and V − J colours have different Eddington ratio distributions. AGN in blue star-forming hosts dominate at relatively high Eddington ratios. In contrast, AGN in red quiescent hosts become increasingly important as a fraction of the total population towards low Eddington ratios. At higher redshift, z > 0.6, such differences are significant at the 2σ level only for sources with Eddington ratios ≳ 10^− 3. These findings are consistent with scenarios in which diverse accretion modes are responsible for the build-up of supermassive black holes at the centres of galaxies. We compare these results with the predictions of theGALFORM semi-analytic model for the cosmological evolution of AGN and galaxies. This model postulates two black hole fuelling modes, the first is linked to star formation events and the second takes place in passive galaxies. GALFORM predicts that a substantial fraction of the black hole growth at z < 1 is associated with quiescent galaxies, in apparent conflict with the observations. Relaxing the strong assumption of the model that passive AGN hosts have zero star formation rate could bring those predictions in better agreement with the data.
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Biotic indices have been developed to summarise information provided by benthic macroinvertebrates, but their use can require specialized taxonomic expertise as well as a time-consuming operation. Using high taxonomic level in biotic indices reduces sampling processing time but should be considered with caution, since assigning tolerance level to high taxonomic levels may cause uncertainty. A methodology for family level tolerance categorization based on the affinity of each family with disturbed or undisturbed conditions was employed. This family tolerance classification approach was tested in two different areas from Mediterranean Sea affected by sewage discharges. Biotic indices employed at family level responded correctly to sewage presence. However, in areas with different communities among stations and high diversity of species within each family, assigning the same tolerance level to a whole family could imply mistakes. Thus, use of high taxonomic level in biotic indices should be only restricted to areas where homogeneous community is presented and families across sites have similar species composition.
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This research paper deals with the evolution of the extracellular polymeric substances (EPS) produced in the mixed liquor of two 25 L bench-scale membrane bioreactors (MBRs), with micro (MF-MBR) and ultrafiltration (UF-MBR) submerged membranes. The conclusion focuses on the relationship between the operation and how EPS respond, demonstrating that significant changes in EPS concentration were commonly observed when abrupt changes in the operational conditions took place. Bound EPS (EPSb) showed moderate positive statistical correlations with sludge age and MLSS for the two MBRs. Soluble EPS (EPSs), on the other hand, showed a moderate negative statistical correlation between EPSs with the two parameters analyzed for MF-MBR and no correlation with the UF-MBR was found. With respect to the composition of EPS, EPSb were mostly made up of proteins (44–46%) whereas in EPSs, the three components (proteins, carbohydrates, and humic substances) appeared in approximately the same proportion. The statistical analysis exhibited strong positive correlations between EPSb and their constituents, however for EPSs, the correlation was strong only with carbohydrates and moderate with humic substances.
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This thesis explores the role of multimodality in language learners’ comprehension, and more specifically, the effects on students’ audio-visual comprehension when different orchestrations of modes appear in the visualization of vodcasts. Firstly, I describe the state of the art of its three main areas of concern, namely the evolution of meaning-making, Information and Communication Technology (ICT), and audio-visual comprehension. One of the most important contributions in the theoretical overview is the suggested integrative model of audio-visual comprehension, which attempts to explain how students process information received from different inputs. Secondly, I present a study based on the following research questions: ‘Which modes are orchestrated throughout the vodcasts?’, ‘Are there any multimodal ensembles that are more beneficial for students’ audio-visual comprehension?’, and ‘What are the students’ attitudes towards audio-visual (e.g., vodcasts) compared to traditional audio (e.g., audio tracks) comprehension activities?’. Along with these research questions, I have formulated two hypotheses: Audio-visual comprehension improves when there is a greater number of orchestrated modes, and students have a more positive attitude towards vodcasts than traditional audios when carrying out comprehension activities. The study includes a multimodal discourse analysis, audio-visual comprehension tests, and students’ questionnaires. The multimodal discourse analysis of two British Council’s language learning vodcasts, entitled English is GREAT and Camden Fashion, using ELAN as the multimodal annotation tool, shows that there are a variety of multimodal ensembles of two, three and four modes. The audio-visual comprehension tests were given to 40 Spanish students, learning English as a foreign language, after the visualization of vodcasts. These comprehension tests contain questions related to specific orchestrations of modes appearing in the vodcasts. The statistical analysis of the test results, using repeated-measures ANOVA, reveal that students obtain better audio-visual comprehension results when the multimodal ensembles are constituted by a greater number of orchestrated modes. Finally, the data compiled from the questionnaires, conclude that students have a more positive attitude towards vodcasts in comparison to traditional audio listenings. Results from the audio-visual comprehension tests and questionnaires prove the two hypotheses of this study.
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From an examination of the instruments of the Common European Asylum System (CEAS) and related policy measures regarding border surveillance and migration management, two interrelated issues stand out as particularly sensitive: Access to asylum and responsibility for refugee protection. The prevailing view, supported by UNHCR and others, is that responsibility for the care of asylum seekers and the determination of their claims falls on the state within whose jurisdiction the claim is made. However, the possibility to shift that responsibility to another state through inter-state cooperation or unilateral mechanisms undertaken territorially as well as abroad has been a matter of great interest to EU Member States and institutions. Initiatives adopted so far challenge the prevailing view and have the potential to undermine compliance with international refugee and human rights law. This note reviews EU action in the field by reference to the relevant legal standards and best practices developed by UNHCR, focusing on the specific problems of climate refugees and access to international protection, evaluating the inconsistencies between the internal and external dimension of asylum policy. Some recommendations for the European Parliament are formulated at the end, including on action in relation to readmission agreements, Frontex engagement rules in maritime operations, Regional Protection Programmes, and resettlement.
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Introduction. The energy sector, especially with regard to the gas trade, is one of the key areas of co-operation between the EU and Russia. However, the form this co-operation has taken has been giving rise to some concern, both in Brussels and in the EU member states. Questions arise as to whether the EU has not become excessively dependent on Russia for energy, and whether the presence of the Russian gas monopoly in the EU does not enable Russian interference with the development of EU energy policy. The objective of this series of OSW reports (for the previous edition,see Gazprom’s expansion in the EU: co-operation or domination? April 2008 – pdf 1.2 MB) is to provide facts which will permit an accurat answer to these questions to be formulated. Over the course of last year, two new factors strongly affected Gazprom’s capability to operate on the EU market. One was the ongoing global economic crisis, which has depressed demand for gas both in Russia and in Europe. Gazprom has cut both its own production and the quantities of gas it purchases from the Central Asian states, and the decrease in export revenues has forced the company to modify some of its current investment plans. Less demand for gas and the need to reduce production are also having a positive impact – the Russian company is likely to avoid the difficulties in meeting all of its export commitments which, only a year or so ago, it was expected to experience. The other factor affecting Gazprom’s expansion in Europe is the observed radicalisation of the rhetoric and actions of both the company itself and of the Russian authorities with regard to the gas sector as broadly understood. The gas crisis between Russia and Ukraine in January 2009, which resulted in a two-week interruption of gas supplies from Russia to Europe via Ukraine, was the most prominent example of this radicalisation. The hardening of rhetoric in the ongoing energy talks with the EU and other actors, and increased political and business activities designed to promote Russian gas interests in Europe, in particular the lobbying for the Nord Stream and South Stream projects, are further signs of this shift in tone. These issues raise the question of whether, and to what extent, the current condition of Gazprom’s finance will permit the company to implement the infrastructural projects it has been endorsing and its other investment plans in Europe. Another important question is whether the currently observed changes in how Gazprom operates will take on a more permanent character, and what consequences this will have for the European Union. The first part of this report discusses Gazprom’s production and export potential. The second comprehensively presents the scope and nature of Gazprom’s economic presence in the EU member states. Finally, the third part presents the Russian company’s methods of operation on foreign markets. The data presented in the report come mainly from the statistics of the International Energy Agency, the European Commission and Gazprom, as well as the Central Bank of Russia and the Russian Statistical Office. The figures presented here also include proprietary calculations by the OSW based on figures disclosed by energy companies and reports by professional press and news agencies.
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For years now Belarus has been a key economic partner for Lithuania and Latvia. These two Baltic states have well-developed port infrastructure and thus provide what are the geographically closest and also the cheapest exit to international outlets for Belarusia’s petrochemical and chemical industries, both of which are export-oriented. As a result, the transit of Belarusian goods is one of the major sources of income for the state budgets of the two countries. This economic interdependence has affected the stance Riga and Vilnius take on Minsk at the EU forum. When in February and March 2012 the Council of the European Union was resolving the issue of imposing economic sanction on selected Belarusian companies which backed Alyaksandr Lukashenka’s regime, this triggered a discussion on what the point of such measures is and on possible economic losses in Lithuania and Latvia. As a result of firm resistance from Latvia (which was backed by Slovenia), the Council removed those companies which were most strongly engaged in co-operation with Latvian partners from the list of those to be covered with economic sanctions. Lithuania, which is more critical of the political situation in Belarus, did not express its official opposition to the sanctions. Despite some differences in the policies adopted by Riga and Vilnius, it turned out that Minsk could count on strong support from local business groups in both of these countries, as these groups fear impediments in this highly profitable co-operation and also retaliation from the Belarusian government. The existing economic bonds mean that neither Vilnius nor Riga have any other choice but to co-operate with Belarus. They must therefore adopt a carefully balanced policy towards Minsk. At the same time, being EU member states, they do not officially deny that a problem exists with the violation of human rights by Alyaksandr Lukashenka’s regime. It is for this reason that the governments of Latvia and Lithuania will be interested in maintaining the status quo in relations with Minsk. On the other hand, Belarus in a way also has no other choice but to use the ports in Lithuania and Latvia, and this will prevent it from excessively escalating tension in relations with these two countries.
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Russia’s increasingly aggressive policy and its enhanced military activity in the Nordic-Baltic region has led to revaluations in Sweden’s and Finland’s security and defence policies and a rethinking of the formats of their military co-operation. While remaining outside NATO, the two states have been developing closer bilateral defence co-operation and working more closely with the United States, while at the same time developing co-operation with NATO. Sweden and Finland perceive the United States as the guarantor of regional and European security. From their point of view, the United States is currently the country that has both the necessary military capabilities and the political will to react in the event of a conflict between Russia and NATO in the Nordic-Baltic region, in which both countries would inevitably become involved despite their non-aligned status. For Sweden and Finland, intensified co-operation with the United States offers an alternative to NATO membership, which is currently out of the question for domestic political reasons. Meanwhile, the US has also become increasingly aware of the strategic importance of the two states, which, for the purposes of contingency planning, are in fact an extension of NATO’s north-eastern flank.
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A comunicação e transmissão de informação sem fios tornou - se uma realidade cada vez mais utilizada pelas sociedades contemporâneas. A nível profissional, as forças armadas de cada país acharam conveniente modernizar os seus meios, por forma a aumentar a eficiência e a segurança em determinadas tarefas. Nesse sentido, o Exército português adquiriu um robot (ROVIM) cuja função é desempenhar ações de reconhecimento e vigilância de modo a obter informações de forma segura. O objetivo desta dissertação é dimensionar e construir uma antena para controlo wireless do robot (ROVIM). As especificações técnicas desta antena requerem dois modos de operação, um com uma largura de feixe larga e outro com uma largura de feixe estreita. Para alcançar esses objetivos dimensionou-se e construiu-se duas antenas. Na dissertação são construídas duas antenas, a primeira é uma antena Yagi – Uda convencional e a segunda é uma antena com uma estrutura nova que permite a regulação do ganho e da largura de feixe a -3 dB. A primeira antena será o modelo base da segunda antena, que apresenta a inovação do controlo das caraterísticas de radiação. Esse controlo é possível através da introdução de díodos e do respetivo circuito de polarização na estrutura da antena. Inicialmente, as antenas foram dimensionadas e simuladas recorrendo ao programa de simulação CST MWS, de modo a operarem na banda dos 2,4 GHz. Após a construção das antenas, as caraterísticas de radiação foram medidas recorrendo à câmara anecoica e ao network analyzer, permitindo assim a comparação dos resultados medidos com os simulados.
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"Published by order of City councils."