959 resultados para active, in nodules


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The Epstein-Barr virus-encoded nuclear antigen EBNA-1 gene promoter for the restricted Epstein-Barr virus (EBV) latency program operating in group I Burkitt lymphoma (BL) cell lines was previously identified incorrectly. Here we present evidence from RACE (rapid amplification of cDNA ends) cloning, reverse transcription-PCR, and S1 nuclease analyses, which demonstrates that the EBNA-1 gene promoter in group I BL cell lines is located in the viral BamHI Q fragment, immediately upstream of two low-affinity EBNA-1 binding sites. Transcripts initiated from this promoter, referred to as Qp, have the previously reported Q/U/K exon splicing pattern. Qp is active in group I BL cell lines but not in group III BL cell lines or in EBV immortalized B-lymphoblastoid cell lines. In addition, transient transfection of Qp-driven reporter constructs into both an EBV-negative BL cell line and a group I BL cell line gave rise to correctly initiated transcripts. Inspection of Qp revealed that it is a TATA-less promoter whose architecture is similar to the promoters of housekeeping genes, suggesting that Qp may be a default promoter which ensures EBNA-1 expression in cells that cannot run the full viral latency program. Elucidation of the genetic mechanism responsible for the EBNA-1-restricted program of EBV latency is an essential step in understanding control of viral latency in EBV-associated tumors.

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Pokeweed antiviral protein (PAP), a 29-kDa protein isolated from Phytolacca americana inhibits translation by catalytically removing a specific adenine residue from the 28S rRNA of eukaryotic ribosomes. PAP has potent antiviral activity against many plant and animal viruses, including human immunodeficiency virus. We describe here development of a positive selection system to isolate PAP mutants with reduced toxicity. In vitro translation in the presence or absence of microsomal membranes shows that PAP is synthesized as a precursor and undergoes at least two different proteolytic processing steps to generate mature PAP. The PAP cDNA was placed under control of the galactose-inducible GAL1 promoter and transformed into Saccharomyces cerevisiae. Induction of PAP expression was lethal to yeast. The PAP expression plasmid was mutagenized and plasmids encoding mutant PAP genes were identified by their failure to kill S. cerevisiae. A number of mutant alleles were sequenced. In one mutant, a point mutation at Glu-177 inactivated enzymatic function in vitro, suggesting that this glutamic acid residue is located at or near the catalytic site. Mutants with either point mutations near the N terminus or a nonsense mutation at residue 237 produced protein that was enzymatically active in vitro, suggesting that the toxicity of PAP is not due solely to enzymatic activity. Toxicity of PAP appears to be a multistep process that involves possibly different domains of the protein.

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The O2 sensitivity of protein expression was assessed in hepatocytes from the western painted turtle. Anoxic cells consistently expressed proteins of 83.0, 70.4, 42.5, 35.3, and 16.1 kDa and suppressed proteins of 63.7, 48.2, 36.9, 29.5, and 17.7 kDa. Except for the 70.4-kDa protein, this pattern was absent during aerobic incubation with 2 mM NaCN, suggesting a specific requirement for O2. Aerobic incubation with Co2+ or Ni2+ increased expression of the 42.5-, 35.3-, and 16.1-kDa protein bands which was diminished with the heme synthesis inhibitor 4,6-dioxoheptanoic acid. Proteins suppressed in anoxia were also suppressed during aerobic incubation with Co2+ or Ni2+ but this was not relieved by 4,6-dioxoheptanoic acid. The anoxia- and Co2+/Ni2+-induced expression of the 42.5-, 35.3-, and 16.1-kDa protein bands was antagonized by 10% CO; however, with the exception of the 17.7-kDa protein, this was not found for any of the O2- or Co2+/Ni2+-suppressed proteins. Anoxia-induced proteins were compared with proteins expressed during heat shock. Heat shock proteins appeared at 90.2, 74.8, 63.4, 25, and 15.5 kDa and were of distinct molecular masses compared with the anoxia-induced proteins. These results suggest that O2-sensing mechanisms are active in the control of protein expression and suppression during anoxia and that, in the case of the 42.5-, 35.3-, 17.7-, and 16.1-kDa proteins, a conformational change in a ferro-heme protein is involved in transducing the O2 signal.

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The opportunistic human pathogen Pseudomonas aeruginosa produces a variety of virulence factors, including exotoxin A, elastase, alkaline protease, alginate, phospholipases, and extracellular rhamnolipids. The previously characterized rhlABR gene cluster encodes a regulatory protein (RhlR) and a rhamnosyltransferase (RhlAB), both of which are required for rhamnolipid synthesis. Another gene, rhII, has now been identified downstream of the rhlABR gene cluster. The putative RhlI protein shares significant sequence similarity with bacterial autoinducer synthetases of the LuxI type. A P. aeruginosa rhlI mutant strain carrying a disrupted rhlI gene was unable to produce rhamnolipids and lacked rhamnosyltransferase activity. Rhamnolipid synthesis was restored by introducing a wild-type rhlI gene into such strains or, alternatively, by adding either the cell-free spent supernatant from a P. aeruginosa wild-type strain or synthetic N-acylhomoserine lactones. Half-maximal induction of rhamnolipid synthesis in the rhlI mutant strain required 0.5 microM N-butyrylhomoserine lactone or 10 microM N-(3-oxohexanoyl)homoserine lactone. The P. aeruginosa rhlA promoter was active in the heterologous host Pseudomonas putida when both the rhlR and rhlI genes were present or when the rhlR gene alone was supplied together with synthetic N-acylhomoserine lactones. The RhlR-RhlI regulatory system was found to be essential for the production of elastase as well, and cross-communication between the RhlR-RhlI rhamnolipid regulatory system and the LasR-LasI elastase regulatory system was demonstrated.

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This hardcover modern binding contains a twenty-page manuscript copy of the salutatory address given by Elisha Cooke at the 1697 Harvard College Commencement. The text includes edits and struck-through words. A one-page copy of the first page of the oration signed by Thomas Banister and William Phips is at the end of the volume.

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This research explores whether civil society organizations (CSOs) can contribute to more effectively regulating the working conditions of temporary migrant farmworkers in North America. This dissertation unfolds in five parts. The first part of the dissertation sets out the background context. The context includes the political economy of agriculture and temporary migrant labour more broadly. It also includes the political economy of the legal regulations that govern immigration and work relations. The second part of the research builds an analytical model for studying the operation of CSOs active in working with the migrant farmworker population. The purpose of the analytical framework is to make sense of real-world examples by providing categories for analysis and a means to get at the channels of influence that CSOs utilize to achieve their aims. To this end, the model incorporates the insights from three significant bodies of literature—regulatory studies, labour studies, and economic sociology. The third part of the dissertation suggests some key strategic issues that CSOs should consider when intervening to assist migrant farmworkers, and also proposes a series of hypotheses about how CSOs can participate in the regulatory process. The fourth part probes and extends these hypotheses by empirically investigating the operation of three CSOs that are currently active in assisting migrant farm workers in North America: the Agricultural Workers Alliance (Canada), Global Workers’ Justice Alliance (USA), and the Coalition of Immokalee Workers (USA). The fifth and final part draws together lessons from the empirical work and concluded that CSOs can fill gaps left by the waning power of actors, such as trade unions and labour inspectorates, as well as act in ways that these traditional actors can not.

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Nuclear factor kappa B (NF-kB) is one of the most important transcription factors whose modulation triggers a cascade of signaling events, namely the expression of many cytokines, enzymes, chemokines, and adhesion molecules, some of which being potential key targets for intervention in the treatment of inflammatory conditions. The 2-styrylchromones (2-SC) designation represents a well-recognized group of natural and synthetic chromones, vinylogues of flavones (2-phenylchromones). Several 2-SC were recently tested for their anti-inflammatory potential, regarding the arachidonic acid metabolic cascade, showing some motivating results. In addition, several flavones with structural similarities to 2-SC have shown NF-kB inhibitory properties. Hence, the aim of the present work was to continue the investigation on the interference of 2-SC in inflammatory pathways. Herein we report their effects on lipopolysaccharide (LPS)-induced NF-kB activation and consequent production of proinflammatory cytokines/chemokine, using a human monocytic cell line (THP-1). From the twelve 2-SC tested, three of them were able to significantly inhibit the NF-kB activation and to reduce the production of the proinflammatory cytokines/chemokine. The compound 3',4',5-trihydroxy-2- styrylchromone stood up as the most active in both assays, being a promising candidate for an anti-inflammatory drug.

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The object of this paper is twofold: to provide a broad descriptive analysis of the risk of collusive behaviour throughout Europe in the manufacturing sector; and to identify those manufacturing sectors in which the European Commission has been more active in the past in its capacity of antitrust authority.

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Summary. On 11 March 2011, a devastating earthquake struck Japan and caused a major nuclear accident at the Fukushima Daiichi nuclear plant. The disaster confirmed that nuclear reactors must be protected even against accidents that have been assessed as highly unlikely. It also revealed a well-known catalogue of problems: faulty design, insufficient back-up systems, human error, inadequate contingency plans, and poor communications. The catastrophe triggered the rapid launch of a major re-examination of nuclear reactor security in Europe. It also stopped in its tracks what had appeared to be a ‘nuclear renaissance’, both in Europe and globally, especially in the emerging countries. Under the accumulated pressure of rising demand and climate warming, many new nuclear projects had been proposed. Since 2011 there has been more ambivalence, especially in Europe. Some Member States have even decided to abandon the nuclear sector altogether. This Egmont Paper aims to examine the reactions of the EU regarding nuclear safety since 2011. Firstly, a general description of the nuclear sector in Europe is provided. The nuclear production of electricity currently employs around 500,000 people, including those working in the supply chain. It generates approximately €70 billion per year. It provides roughly 30% of the electricity consumed in the EU. At the end of 2013, there were 131 nuclear power reactors active in the EU, located in 14 countries. Four new reactors are under construction in France, Slovakia and Finland. Secondly, this paper will present the Euratom legal framework regarding nuclear safety. The European Atomic Energy Community (EAEC or Euratom) Treaty was signed in 1957, and somewhat obscured by the European Economic Community (EEC) Treaty. It was a more classical treaty, establishing institutions with limited powers. Its development remained relatively modest until the Chernobyl catastrophe, which provoked many initiatives. The most important was the final adoption of the Nuclear Safety Directive 2009/71. Thirdly, the general symbiosis between Euratom and the International Atomic Energy Agency (IAEA) will be explained. Fourthly, the paper analyses the initiatives taken by the EU in the wake of the Fukushima catastrophe. These initiatives are centred around the famous ‘stress tests’. Fifthly, the most important legal change brought about by this event was the revision of Directive 2009/71. Directive 2014/87 has been adopted quite rapidly, and has deepened in various ways the role of the EU in nuclear safety. It has reinforced the role and effective independence of the national regulatory authorities. It has enhanced transparency on nuclear safety matters. It has strengthened principles, and introduced new general nuclear safety objectives and requirements, addressing specific technical issues across the entire life cycle of nuclear installations, and in particular, nuclear power plants. It has extended monitoring and the exchange of experiences by establishing a European system of peer reviews. Finally, it has established a mechanism for developing EU-wide harmonized nuclear safety guidelines. In spite of these various improvements, Directive 2014/87 Euratom still reflects the ambiguity of the Euratom system in general, and especially in the field of nuclear safety. The use of nuclear energy remains controversial among Member States. Some of them remain adamantly in favour, others against or ambivalent. The intervention of the EAEC institutions remains sensitive. The use of the traditional Community method remains limited. The peer review method remains a very peculiar mechanism that deserves more attention.

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An initial investigation has been undertaken on the chemical composition of the manganese nodules. The results of chemical analyses on each layer of single nodules reveal the periodic patterns of distribution for Mn, Fe, Cu, Pb, Zn, Ni and Co contents. The variations strongly suggest that those of the elements in nodules from this region are, at least, climatically controlled.

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Manganese nodules from the Suiko Seamount exhibit the significant characteristics in mineral compositions. Well crystallized todorokite and birnessite, which are principal manganese mineral phase in nodules, only occur in the oxide layer directly incasing pebbles and coarse sand. The preferential formation of todorokite or birnessite phases seem to be principally controlled by the reaction rate of iron-manganese oxides with trace elements such as Cu, Ni, Co, Zn, Pb concentrated in nodules, rather than redox characteristics of sedimentary environment or mineralogical diagenetic process.

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Wetlands are extremely valuable natural features that have decreased significantly in number over time in Illinois and the United States ... Their important functions include flood protection, water conservation in times of drought, groundwater recharge, improvement of water quality through sediment reduction and contaminant removal, and providing habitat for native animals and plants, including many sensitive and state-listed threatened and endangered species ... Due to a federal "no net loss" policy on wetlands adopted through executive order by President George H. Bush in 1990, as well as a prevailing heightened interest in conservation in general, there is currently considerable interest in the restoration and creation of wetlands. Both Section-404 of the Clean Water Act of 1972 and the Swampbuster Provision of the Food Securities Act of 1985 require compensation or mitigation for the loss of wetlands. A number of federal and state programs such as Section 319 of the Clean Water Act and the Conservation Reserve Program within the Natural Resources Conservation Service (NRCS) encourage wetland restoration and creation. In addition, various conservation organizations, such as The Nature Conservancy and Ducks Unlimited are very active in wetland restoration. Despite wetland restoration efforts and the national goal of no net loss, wetlands and wetland functions continue to be lost due to degradation of existing wetlands ... Unfortunately, no reliable information exists on the quality of existing wetlands or on trends in wetland quality over time ... The functional quality of existing wetlands is likely decreasing in many areas due to the combined effects of habitat fragmentation, alteration of hydrology, invasive species, and continued input of nutrients and pollutants. Furthermore, it is still debatable whether created or restored wetlands can adequately replace the suite of ecological functions provided by natural wetlands ... and the failure of many wetland compensation projects contributes to a continued national net loss of wetland functions ... The need for post-construction site monitoring and assessment of created and restored wetlands to evaluate functional success is widely recognized. ... At this time, there is little agreement on how to assess the success on quality of wetland restorations or creations.

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In this report, the Commission examines developments relevant to the competitiveness of the retail and wholesale markets. In the retail market, two key indicators of activity are examined: The first indicator is the rate of customer switching from bundled services to "delivery services." Customers taking delivery services are either purchasing power and energy from ARES or are purchasing power and energy from the host utility on an "unbundled" basis under the utility's delivery services tariffs. Currently, bundled power sales mainly consist of sales to customers under the Sec. 16-110 "Power Purchase Option" (PPO). The second indicator of retail activity presented in this report is the number of suppliers active in the State's nine service territories.

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The thiol tripeptides, glutathione (GSH) and homoglutathione (hGSH), perform multiple roles in legumes, including protection against toxicity of free radicals and heavy metals. The three genes involved in the synthesis of GSH and hGSH in the model legume, Lotus japonicus, have been fully characterized and appear to be present as single copies in the genome. The gamma-glutamylcysteine synthetase (gammaecs) gene was mapped on the long arm of chromosome 4 (70.0 centimorgans [cM]) and consists of 15 exons, whereas the glutathione synthetase (gshs) and homoglutathione synthetase (hgshs) genes were mapped on the long arm of chromosome 1 (81.3 cM) and found to be arranged in tandem, with a separation of approximately 8 kb. Both genes consist of 12 exons of exactly the same size (except exon 1, which is similar). Two types of transcripts were detected for the gshs gene, which putatively encode proteins localized in the plastids and cytosol. Promoter regions contain cis-acting regulatory elements that may be involved in the plant's response to light, hormones, and stress. Determination of transcript levels, enzyme activities, and thiol contents in nodules, roots, and leaves revealed that gammaecs and hgshs are expressed in all three plant organs, whereas gshs is significantly functional only in nodules. This strongly suggests an important role of GSH in the rhizobia-legume symbiosis.

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Additions of strontium to hypoeutectic aluminum-silicon alloys modify the morphology of the eutectic silicon phase from a coarse platelike structure to a fine fibrous structure. Thermal analysis, interrupted solidification, and microstructural examination of sand castings in this work revealed that, in addition to a change in silicon morphology, modification with strontium also causes an increase in the size of eutectic grains. The eutectic grain size increases because fewer grains nucleate, possibly due to poisoning of the phosphorus-based nucleants, that are active in the unmodified alloy. A simple growth model is developed to estimate the interface velocity during solidification of a eutectic grain. The model confirms, independent of microstructural observations, that the addition of 100 ppm strontium increases the eutectic grain size by at least an order of magnitude compared with the equivalent unmodified alloy. The model predicts that the growth velocity varies significantly during eutectic growth. At low strontium levels, these variations may be sufficient to cause transitions between flake and fibrous silicon morphologies depending on the casting conditions. The model can be used to rationally interpret the eutectic grain structure and silicon morphology of fully solidified aluminum-silicon castings and, when coupled with reliable thermal data, can be used to estimate the eutectic grain size.