952 resultados para Functions of Documentary Credit
Resumo:
To study the macroeconomic effects of unconventional monetary policy across the different countries of the eurozone, I develop an identification scheme to disentangle conventional from non-conventional policy shocks, using futures contracts on overnight interest rates and the size of the European Central Bank balance sheet. Setting these shocks as endogenous variables in a structural vector autoregressive (SVAR) model, along with the CPI and the employment rate, estimated impulse response functions of policy to macroeconomic variables are studied. I find that unconventional policy shocks generated mixed effects in inflation but had a positive impact on employment, with the exception of Portugal, Spain, Greece and Italy where the employment response is close to zero or negative. The heterogeneity that characterizes the responses shows that the monetary policy measures taken in recent years were not sufficient to stabilize the economies of the eurozone countries under more severe economic conditions.
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The purpose of this work is to develop a practicable approach for Telecom firms to manage the credit risk exposition to their commercial agents’ network. Particularly it will try to approach the problem of credit concession to clients’ from a corporation perspective and explore the particular scenario of agents that are part of the commercial chain of the corporation and therefore are not end-users. The agents’ network that served as a model for the presented study is composed by companies that, at the same time, are both clients and suppliers of the Telecommunication Company. In that sense the credit exposition analysis must took into consideration all financial fluxes, both inbound and outbound. The current strain on the Financial Sector in Portugal, and other peripheral European economies, combined with the high leverage situation of most companies, generates an environment prone to credit default risk. Due to these circumstances managing credit risk exposure is becoming increasingly a critical function for every company Financial Department. The approach designed in the current study combined two traditional risk monitoring tools: credit risk scoring and credit limitation policies. The objective was to design a new credit monitoring framework that is more flexible, uses both external and internal relationship history to assess risk and takes into consideration commercial objectives inside the agents’ network. Although not explored at length, the blueprint of a Credit Governance model was created for implementing the new credit monitoring framework inside the telecom firm. The Telecom Company that served as a model for the present work decided to implement the new Credit Monitoring framework after this was presented to its Executive Commission.
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MicroRNAs (miRNAs) have been shown to play important roles in both brain development and the regulation of adult neural cell functions. However, a systematic analysis of brain miRNA functions has been hindered by a lack of comprehensive information regarding the distribution of miRNAs in neuronal versus glial cells. To address this issue, we performed microarray analyses of miRNA expression in the four principal cell types of the CNS (neurons, astrocytes, oligodendrocytes, and microglia) using primary cultures from postnatal d 1 rat cortex. These analyses revealed that neural miRNA expression is highly cell-type specific, with 116 of the 351 miRNAs examined being differentially expressed fivefold or more across the four cell types. We also demonstrate that individual neuron-enriched or neuron-diminished RNAs had a significant impact on the specification of neuronal phenotype: overexpression of the neuron-enriched miRNAs miR-376a and miR-434 increased the differentiation of neural stem cells into neurons, whereas the opposite effect was observed for the glia-enriched miRNAs miR-223, miR-146a, miR-19, and miR-32. In addition, glia-enriched miRNAs were shown to inhibit aberrant glial expression of neuronal proteins and phenotypes, as exemplified by miR-146a, which inhibited neuroligin 1-dependent synaptogenesis. This study identifies new nervous system functions of specific miRNAs, reveals the global extent to which the brain may use differential miRNA expression to regulate neural cell-type-specific phenotypes, and provides an important data resource that defines the compartmentalization of brain miRNAs across different cell types.
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We have used massively parallel signature sequencing (MPSS) to sample the transcriptomes of 32 normal human tissues to an unprecedented depth, thus documenting the patterns of expression of almost 20,000 genes with high sensitivity and specificity. The data confirm the widely held belief that differences in gene expression between cell and tissue types are largely determined by transcripts derived from a limited number of tissue-specific genes, rather than by combinations of more promiscuously expressed genes. Expression of a little more than half of all known human genes seems to account for both the common requirements and the specific functions of the tissues sampled. A classification of tissues based on patterns of gene expression largely reproduces classifications based on anatomical and biochemical properties. The unbiased sampling of the human transcriptome achieved by MPSS supports the idea that most human genes have been mapped, if not functionally characterized. This data set should prove useful for the identification of tissue-specific genes, for the study of global changes induced by pathological conditions, and for the definition of a minimal set of genes necessary for basic cell maintenance. The data are available on the Web at http://mpss.licr.org and http://sgb.lynxgen.com.
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In Saccharomyces cerevisiae, TBF1, an essential gene, influences telomere function but also has other roles in the global regulation of transcription. We have identified a new member of the tbf1 gene family in the mammalian pathogen Pneumocystis carinii. We demonstrate by transspecies complementation that its ectopic expression can provide the essential functions of Schizosaccharomyces pombe tbf1 but that there is no rescue between fission and budding yeast orthologues. Our findings indicate that an essential function of this family of proteins has diverged in the budding and fission yeasts and suggest that effects on telomere length or structure are not the primary cause of inviability in S. pombe tbf1 null strains.
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L'ubiquitination est une modification des protéines conservée, consistant en l'addition de résidus « ubiquitine » et régulant le destin cellulaire des protéines. La protéine « TRAF-interacting protein » TRAIP (ou TRIP) est une ligase E3 qui catalyse l'étape finale de l'ubiquitination. TRAIP est conservé dans l'évolution et est nécessaire au développement des organismes puisque l'ablation de TRAIP conduit à la mort embryonnaire aussi bien de la drosophile que de la souris. De plus, la réduction de l'expression de TRAIP dans des kératinocytes épidermiques humains réprime la prolifération cellulaire et induit un arrêt du cycle cellulaire en phase Gl, soulignant le lien étroit entre TRAIP et la prolifération cellulaire. Comme les mécanismes de régulation de la prolifération jouent un rôle majeur dans l'homéostasie de la peau, il est important de caractériser la fonction de TRAIP dans ces mécanismes. En utilisant des approches in vitro, nous avons déterminé que la protéine TRAIP est instable, modifiée par l'addition d'ubiquitine et ayant une demi-vie d'environ 4 heures. Nos analyses ont également révélé que l'expression de TRAIP est dépendante du cycle cellulaire, atteignant un pic d'expression en phase G2/M et que l'induction de son expression s'effectue principalement au cours de la transition Gl/S. Nous avons identifié le facteur de transcription E2F1 comme en étant le responsable, en régulant directement le promoteur de TRAIP. Aussi, TRAIP endogène ou surexprimée est surtout localisée au niveau du nucléole, une organelle nucléaire qui est désassemblée pendant la division cellulaire. Pour examiner la localisation subcellulaire de TRAIP pendant la mitose, nous avons imagé la protéine TRAIP fusionnée à une protéine fluorescente, à l'intérieur de cellules vivantes nommées HeLa, à l'aide d'un microscope confocal. Dans ces conditions, TRAIP est majoritairement localisée autour des chromosomes en début de mitose, puis est arrangée au niveau de l'ADN chromosomique en fin de mitose. La détection de TRAIP endogène à l'aide d'un anticorps spécifique a confirmé cette localisation. Enfin, l'inactivation de TRAIP dans les cellules HeLa par interférence ARN a inhibé leur capacité à s'arrêter en milieu de mitose. Nos résultats suggèrent que le mécanisme sous-jacent peut être lié au point de contrôle de l'assemblage du fuseau mitotique. - Ubiquitination of proteins is a post-translational modification which decides the cellular fate of the protein. The TRAF-interacting protein (TRAIP, TRIP) functions as an E3 ubiquitin ligase mediating addition of ubiquitin moieties to proteins. TRAIP interacts with the deubiquitinase CYLD, a tumor suppressor whose functional inactivation leads to skin appendage tumors. TRAIP is required for early embryonic development since removal of TRAIP either in Drosophila or mice by mutations or knock¬out is lethal due to aberrant regulation of cell proliferation and apoptosis. Furthermore, shRNA- mediated knock-down of TRAIP in human epidermal keratinocytes (HEK) repressed cell proliferation and induced a Gl/S phase block in the cell cycle. Additionally, TRAIP expression is strongly down- regulated during keratinocyte differentiation supporting the notion of a tight link between TRAIP and cell proliferation. We thus examined the biological functions of TRAIP in epithelial cell proliferation. Using an in vitro approach, we could determine that the TRAIP protein is unstable, modified by addition of ubiquitin moieties after translation and exhibits a half-life of 3.7+/-1-6 hours. Our analysis revealed that the TRAIP expression is modulated in a cell-cycle dependent manner, reaching a maximum expression level in G2/M phases. In addition, the expression of TRAIP was particularly activated during Gl/S phase transition and we could identify the transcription factor E2F1 as an activator of the TRAIP gene promoter. Both endogenous and over-expressed TRAIP mainly localized to the nucleolus, a nuclear organelle which is disassembled during cell division. To examine the subcellular localization of TRAIP during M phase, we performed confocal live-cell imaging of a functional fluorescent protein TRAIP-GFP in HeLa cells. TRAIP was distributed in the cytoplasm and accumulated around mitotic chromosomes in pro- and meta-phasic cells. TRAIP was then confined to chromosomal DNA location in anaphase and later phases of mitosis. Immune-detection of endogenous TRAIP protein confirmed its particular localization in mitosis. Finally, inactivating TRAIP expression in HeLa cells using RNA interference abrogated the cells ability to stop or delay mitosis progression. Our results suggested that TRAIP may involve the spindle assembly checkpoint.
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Plasmacytoid dendritic cells (pDCs) were first described as interferon-producing cells and, for many years, their overlapping characteristics with both lymphocytes and classical dendritic cells (cDCs) created confusion over their exact ontogeny. In this Viewpoint article, Nature Reviews Immunology asks five leaders in the field to discuss their thoughts on the development and functions of pDCs--do these cells serve mainly as a major source of type I interferons or do they also make other important contributions to immune responses?
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Chronic disorders, such as obesity, diabetes, inflammation, non-alcoholic fatty liver disease and atherosclerosis, are related to alterations in lipid and glucose metabolism, in which peroxisome proliferator-activated receptors (PPAR)α, PPARβ/δ and PPARγ are involved. These receptors form a subgroup of ligand-activated transcription factors that belong to the nuclear hormone receptor family. This review discusses a selection of novel PPAR functions identified during the last few years. The PPARs regulate processes that are essential for the maintenance of pregnancy and embryonic development. Newly found hepatic functions of PPARα are the mediation of female-specific gene repression and the protection of the liver from oestrogen induced toxicity. PPARα also controls lipid catabolism and is the target of hypolipidaemic drugs, whereas PPARγ controls adipocyte differentiation and regulates lipid storage; it is the target for the insulin sensitising thiazolidinediones used to treat type 2 diabetes. Activation of PPARβ/δ increases lipid catabolism in skeletal muscle, the heart and adipose tissue. In addition, PPARβ/δ ligands prevent weight gain and suppress macrophage derived inflammation. In fact, therapeutic benefits of PPAR ligands have been confirmed in inflammatory and autoimmune diseases, such as encephalomyelitis and inflammatory bowel disease. Furthermore, PPARs promote skin wound repair. PPARα favours skin healing during the inflammatory phase that follows injury, whilst PPARβ/δ enhances keratinocyte survival and migration. Due to their collective functions in skin, PPARs represent a major research target for our understanding of many skin diseases. Taken altogether, these functions suggest that PPARs serve as physiological sensors in different stress situations and remain valuable targets for innovative therapies.
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Calpain 3 is a member of the calpain family of calcium-dependent intracellular proteases. Thirteen years ago it was discovered that mutations in calpain 3 (CAPN3) result in an autosomal recessive and progressive form of limb girdle muscular dystrophy called limb girdle muscular dystrophy type 2A. While calpain 3 mRNA is expressed at high levels in muscle and appears to have some role in developmental processes, muscles of patients and mice lacking calpain 3 still form apparently normal muscle during prenatal development; thus, a functional calpain 3 protease is not mandatory for muscle to form in vivo but it is a pre-requisite for muscle to remain healthy. Despite intensive research in this field, the physiological substrates of the calpain 3 protein (hereafter referred to as CAPN3) and its alternatively spliced isoforms remain elusive. The existence of these multiple isoforms complicates the search for the physiological functions of CAPN3 and its pathophysiological role. In this review, we summarize the genetic and biochemical evidence that point to loss of function of the full-length isoform of CAPN3, also known as p94, as the pathogenic isoform. We also argue that its natural substrates must reside in its proximity within the sarcomere where it is stored in an inactive state anchored to titin. We further propose that CAPN3 has many attributes that make it ideally suited as a sensor of sarcomeric integrity and function, involved in its repair and maintenance. Loss of these CAPN3-mediated activities can explain the "progressive" development of muscular dystrophy.
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One of the various functions of proteins in biological systems is the transport of small molecules, for this purpose proteins have naturally evolved special mechanisms to allow both ligand binding and its subsequent release to a target site; a process fundamental to many biological processes. Transport of Vitamin E (a-tocopherol), a lipid soluble antioxidant, to membranes helps in the protection of polyunsaturated fatty acids against peroxidative damage. In this research, the ligand binding characteristics of several members of the CRALTRIO family of lipid binding proteins was examined; the recombinant human a-Tocopherol Transfer Protein (a-TIP), Supernatant Protein Factor (SPF)ffocopherol Associated Protein (TAP), Cellular Retinaldehyde Binding Protein (CRALBP) and the phosphatidylinositol transfer protein from S. cerevisiae Sec 14p. Recombinant Sec 14p was expressed and purified from E. coli for comparison of tocopherol binding to the two other recombinant proteins postulated to traffic a-tocopherol. Competitive binding assays using [3H]-a-tocopherol and Lipidex-l000 resin allowed determination of the dissociation constants ~) of the CRAL-TRIO proteins for a-tocopherol and - 20 hydrophobic ligands for evaluation of the possible biological relevance of the binding interactions observed. The KIs (nM) for RRR-a-tocopherol are: a-TIP: 25.0, Sec 14p: 373, CRALBP: 528 and SPFffAP: 615. This indicates that all proteins recognize tocopherol but not with the same affinity. Sec 14p bound its native ligand PI with a KI of381 whereas SPFffAP bound PI (216) and y-tocopherol (268) similarly in contrast to the preferential binding ofRRR-a-tocopherol by a-TIP. Efforts to adequately represent biologically active SPFff AP involved investigation of tocopherol binding for several different recombinant proteins derived from different constructs and in the presence of different potential modulators (Ca+2, Mg+2, GTP and GDP); none of these conditions enhanced or inhibited a-tocopherol binding to SPF. This work suggests that only aTTP serves as the physiological mediator of a-tocopherol, yet structural homology between proteins allows common recognition of similar ligand features. In addition, several photo-affmity analogs of a-tocopherol were evaluated for their potential utility in further elucidation of a-TTP function or identification of novel tocopherol binding proteins.
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The rate of decrease in mean sediment size and weight per square metre along a 54 km reach of the Credit River was found to depend on variations in the channel geometry. The distribution of a specific sediment size consist of: (1) a transport zone; (2) an accumulation zone; and (3) a depletion zone. These zones shift downstream in response to downcurrent decreases in stream competence. Along a .285 km man-made pond, within the Credit River study area, the sediment is also characterized by downstream shifting accumulation zones for each finer clast size. The discharge required to initiate movement of 8 cm and 6 cm blocks in Cazenovia Creek is closely approximated by Baker and Ritter's equation. Incipient motion of blocks in Twenty Mile Creek is best predicted by Yalin's relation which is more efficient in deeper flows. The transport distance of blocks in both streams depends on channel roughness and geometry. Natural abrasion and distribution of clasts may depend on the size of the surrounding sediment and variations in flow competence. The cumulative percent weight loss with distance of laboratory abraded dolostone is defined by a power function. The decrease in weight of dolostone follows a negative exponential. In the abrasion mill, chipping causes the high initial weight loss of dolostone; crushing and grinding produce most of the subsequent weight loss. Clast size was found to have little effect on the abrasion of dolostone within the diameter range considered. Increasing the speed of the mill increased the initial amount of weight loss but decreased the rate of abrasion. The abrasion mill was found to produce more weight loss than stream action. The maximum percent weight loss determined from laboratory and field abrasion data is approximately 40 percent of the weight loss observed along the Credit River. Selective sorting of sediment explains the remaining percentage, not accounted for by abrasion.
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This investigation comprises a comparison of experimental and theoretical dechanneling of MeV protons in copper single crystals. Dechanneling results when an ion's transverse energy increases to the value where the ion can undergo small impact parameter collisions with individual atoms. Depth dependent dechanneling rates were determined as functions of lattice temperature, ion beam energy and crystal axis orientation. Ion beam energies were IMeV and 2MeV,temperatures ranged from 35 K to 280 K and the experiment was carried out along both the (lOa) and <110) axes. Experimental data took the form of aligned and random Rutherford backscattered energy spectra. Dechanneling rates were extracted from these spectra using a single scattering theory that took explicit account of the different stopping powers experienced by channeled and dechanneled ions and also included a correction factor to take into account multiple scattering effects along the ion's trajectory. The assumption of statistical equilibrium and small angle scattering of the channeled ions allows a description of dechanneling in terms of the solution of a diffusion like equation which contains a so called diffusion function. The diffusion function is shown to be related to the increase in average transverse energy. Theoretical treatments of increase in average transverse energy due to collisions of projectiles with channel electrons and thermal perturbations in the lattice potential are reviewed. Using the diffusion equation and the electron density in the channel centre as a fitting parameter dechanneling rates are extracted. Excellent agreement between theory and experiment has been demonstrated. Electron densities determined in the fitting procedure appear to be realistic. The surface parameters show themselves to be good indicators of the quality of the crystal.
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Jet-cooled, laser-induced phosphorescence excitation spectra (LIP) of thioacetaldehyde CH3CHS, CH3CDS, CD3CHS and CD3CDS have been observed over the region 15800 - 17300 cm"^ in a continuous pyrolysis jet. The vibronic band structure of the singlet-triplet n -* n* transition were attributed to the strong coupling of the methyl torsion and aldehydic hydrogen wagging modes . The vibronic peaks have been assigned in terms of two upper electronic state (T^) vibrations; the methyl torsion mode v^g, and the aldehydic hydrogen wagging mode v^^. The electronic origin O^a^ is unequivocally assigned as follows: CH3CHS (16294.9 cm"'' ), CH3CDS (16360.9 cm"'' ), CD3CHS (16299.7 cm"^ ), and CD3CDS (16367.2 cm"'' ). To obtain structural and dynamical information about the two electronic states, potential surfaces V(e,a) for the 6 (methyl torsion) and a (hydrogen wagging) motions were generated by ab initio quantum mechanical calculations with a 6-3 IG* basis in which the structural parameters were fully relaxed. The kinetic energy coefficients BQ(a,e) , B^(a,G) , and the cross coupling term B^(a,e) , were accurately represented as functions of the two active coordinates, a and 9. The calculations reveal that the molecule adopts an eclipsed conformation for the lower Sq electronic state (a=0°,e=0"') with a barrier height to internal rotation of 541.5 cm"^ which is to be compared to 549.8 cm"^ obtained from the microwave experiment. The conformation of the upper T^ electronic state was found to be staggered (a=24 . 68° ,e=-45. 66° ) . The saddle point in the path traced out by the aldehyde wagging motion was calculated to be 175 cm"^ above the equilibrium configuration. The corresponding maxima in the path taken by methyl torsion was found to be 322 cm'\ The small amplitude normal vibrational modes were also calculated to aid in the assignment of the spectra. Torsional-wagging energy manifolds for the two states were derived from the Hamiltonian H(a,e) which was solved variationally using an extended two dimensional Fourier expansion as a basis set. A torsionalinversion band spectrum was derived from the calculated energy levels and Franck-Condon factors, and was compared with the experimental supersonic-jet spectra. Most of the anomalies which were associated with the interpretation of the observed spectrum could be accounted for by the band profiles derived from ab initio SCF calculations. A model describing the jet spectra was derived by scaling the ab initio potential functions. The global least squares fitting generates a triplet state potential which has a minimum at (a=22.38° ,e=-41.08°) . The flatter potential in the scaled model yielded excellent agreement between the observed and calculated frequency intervals.
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The following thesis presents an analysis of business-government relations within a neo-Marxist framework. Specifically, the discussion encompasses how the business interest group. the Business Council on National Issues, maintains consensus and unity amongst its monopoly capital members. Furthermore. the study elaborates on the process through which the group's interests are acknowledged and legitimized by the state under the "public interest" f8fue. Most of the literature pertaining to business-government relations within the context of interactions between business interest groups and the state, and such specific branches of the state as the government and/or the civil service. emphasize a liberal-pluralist perspective. Essentially, these writings serve to reflect and legitimate the current slatus quo. Marxist discourses on the subject, while attempting to transcend the liberal-pluralist framework. nevertheless suffer from either economic determinism .. ie., stressing the state's accumulation function but not its legitimation function or historical specificity. A cogent and comprehensive neo-Marxist analysis of business-government relations must discuss both the accumulation and legitimation functions of the state. The process by which the concerns of a particular business interest group become part of the state's policy agenda and subsequently are formulated and implemented into policies which legitimate its dominance is also studied. This inquiry is significant given the liberal-pluralist assumptions of a neutral state and that all interest groups compete "on a level playing field". The author's neo-Marxist paradigm rejects both of these assumptions. Building on concepts from nea-Marxist instrumentalism. structuralism. state monopoly capitalism, and forms and functions of the state perspectives. the author proposes that policies which legitimize the interests of the monopoly capital fraction cannot. be discerned only from the state's activities. per StJ. Clearly, if the liberal-pluralist 3 contention of multiple and conflicting interest groups, including those within the capitalist class, is taken at face value, M interest group such as the Business Council on National Issues (BCND, must somehow maintain. internal consensus Md unity amongst its members. Internal consensus amongst its members ensures that the state can better acknowledge and articulate its concerns into policies that maintain hegemonic dominance of the monopoly capital fraction under the "public interest" fllf.JJdq. The author contends that the BCNI focuses most of its interactions on the upper echelons of the civil service since it is this branch of the state which is most responsible for policy formulation and implementation. The author's paradigm is applied within the context of extensively analyzing newspaper coverage. BCN! publications, and other published sources, as well as a personal interview with an executive administrative member of the BeNI. The discussion focuses on how agreement and unity amongst the various interests of the monopoly capital fraction are maintained through the business organization, its policy scope, and finally its interactions with the state. The analysis suggests that while the civil service is an important player in expressing the interests of the BCNI's membership through policies which ostensibly also reflect the "public interest", it is not the only strategic target for the BCNI's interactions with the state. The author's research also highlights the importance of government officials at the Cabinet level and Cabinet Committees. Senior elected officials from the Federal government are also significant in avoiding intergovernmental or interprovincial conflict in implementing policies that legitimize hegemonic dominance of the monopoly capital fraction over other fractions and classes.
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This thesis examines physicians’ satisfaction with electronic medical records (EMRs) in the post-adoption phase. More specifically, the study examines how physicians’ satisfaction with EMRs impacts on their intention to continue using as well as extend their adoption of additional functions of EMRs. Expectation-confirmation theory is used with the incorporation of perceived risk as the theoretical framework. The extended theoretical model is used to formulate eight hypotheses to aid in the understanding of physicians’ continuance intentions. A field survey of 135 Canadian physicians that utilize EMRs was performed to test the model empirically. The study found that physicians are willing to continue using and adopting additional components of EMRs. In addition, the empirical results suggest that physicians’ perceived usefulness and perceived risk impacts satisfaction, which in turn influences physicians’ continuance intentions. As well, perceived risk has an influence on physicians’ continuance intentions directly.