902 resultados para T-Lymphocytes, Regulatory -- immunology


Relevância:

20.00% 20.00%

Publicador:

Resumo:

A small group of phytoplankton species that produce toxic or allelopathic chemicals has a significant effect on plankton dynamics in marine ecosystems. The species of non-toxic phytoplankton, which are large in number, are affected by the toxin-allelopathy of those species. By analysis of the abundance data of marine phytoplankton collected from the North-West coast of the Bay of Bengal, an empirical relationship between the abundance of the potential toxin-producing species and the species diversity of the non-toxic phytoplankton is formulated. A change-point analysis demonstrates that the diversity of non-toxic phytoplankton increases with the increase of toxic species up to a certain level. However, for a massive increase of the toxin-producing species the diversity of phytoplankton at species level reduces gradually. Following the results, a deterministic relationship between the abundance of toxic phytoplankton and the diversity of non-toxic phytoplankton is developed. The abundance–diversity relationship develops a unimodal pathway through which the abundance of toxic species regulates the diversity of phytoplankton. These results contribute to the current understanding of the coexistence and biodiversity of phytoplankton, the top-down vs. bottom-up debate, and to that of abundance–diversity relationship in marine ecosystems.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Gene expression is a quantitative trait that can be mapped genetically in structured populations to identify expression quantitative trait loci (eQTL). Genes and regulatory networks underlying complex traits can subsequently be inferred. Using a recently released genome sequence, we have defined cis- and trans-eQTL and their environmental response to low phosphorus (P) availability within a complex plant genome and found hotspots of trans-eQTL within the genome. Interval mapping, using P supply as a covariate, revealed 18,876 eQTL. trans-eQTL hotspots occurred on chromosomes A06 and A01 within Brassica rapa; these were enriched with P metabolism-related Gene Ontology terms (A06) as well as chloroplast-and photosynthesis-related terms (A01). We have also attributed heritability components to measures of gene expression across environments, allowing the identification of novel gene expression markers and gene expression changes associated with low P availability. Informative gene expression markers were used to map eQTL and P use efficiency-related QTL. Genes responsive to P supply had large environmental and heritable variance components. Regulatory loci and genes associated with P use efficiency identified through eQTL analysis are potential targets for further characterization and may have potential for crop improvement.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The financial crisis of 2007–2009 and the resultant pressures exerted on policymakers to prevent future crises have precipitated coordinated regulatory responses globally. A key focus of the new wave of regulation is to ensure the removal of practices now deemed problematic with new controls for conducting transactions and maintaining holdings. There is increasing pressure on organizations to retire manual processes and adopt core systems, such as Investment Management Systems (IMS). These systems facilitate trading and ensure transactions are compliant by transcribing regulatory requirements into automated rules and applying them to trades. The motivation of this study is to explore the extent to which such systems may enable the alteration of previously embedded practices. We researched implementations of an IMS at eight global financial organizations and found that overall the IMS encourages responsible trading through surveillance, monitoring and the automation of regulatory rules and that such systems are likely to become further embedded within financial organizations. We found evidence that some older practices persisted. Our study suggests that the institutionalization of technology-induced compliant behaviour is still uncertain.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper seeks to discuss EU policies relating to securities markets, created in the wake of the financial crisis and how ICT and specifically e-Government can be utilised within this context. This study utilises the UK as a basis for our discussion. The recent financial crisis has caused a change of perspective in relation to government services and polices. The regulation of the financial sector has been heavily criticised and so is undergoing radical change in the UK and the rest of Europe. New regulatory bodies are being defined with more focus on taking a risk-based system-wide approach to regulating the financial sector. This approach aims to prevent financial institutions becoming too big to fail and thus require massive government bail outs. In addition, a new wave of EU regulation is in the wind to update risk management practices and to further protect investors. This paper discusses the reasons for the financial crisis and the UK’s past and future regulatory landscape. The current and future approach and strategies adopted by the UK’s financial regulators are reviewed as is the lifecycle of EU Directives. The regulatory responses to the crisis are discussed and upcoming regulatory hotspots identified. Discussion of these issues provides the context for our evaluation of the role e-Government and ICT in improving the regulatory system. We identify several processes, which are elementary for regulatory compliance and discuss how ICT is elementary in their implementation. The processes considered include those required for internal control and monitoring, risk management, record keeping and disclosure to regulatory bodies. We find these processes offer an excellent opportunity to adopt an e-Government approach to improve services to both regulated businesses and individual investors through the benefits derived from a more effective and efficient regulatory system.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The financial crisis of 2007-2009, has precipitated large scale regulatory change. Financial organizations are faced with implementing new regulations of considerable breadth and depth. Firms are faced with engaging in complex and costly change management programs at a time when profits are diminished. Furthermore, investors are becoming increasingly focused on compliance are seeking to ensure that organizations can demonstrate robust compliance practices as part of their due diligence process .The role of IS in underpinning stable, is paramount. IS allows the stable and consistent controls for meeting regulations in order to ensure long term effective compliance. Consequently, our study explores the IS capabilities which support the post crisis regulatory landscape. We identify eight key capabilities: Managing Internal Controls, Measuring Monitoring and Reporting Transactions, IS Development and Procurement, Managing Third Parties, Sharing and Selecting Best Practice, IS Leadership, Data Management and Enabling Cultural Change.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The financial crisis of 2007-2009 and the subsequent reaction of the G20 have created a new global regulatory landscape. Within the EU, change of regulatory institutions is ongoing. The research objective of this study is to understand how institutional changes to the EU regulatory landscape may affect corresponding institutionalized operational practices within financial organizations and to understand the role of agency within this process. Our motivation is to provide insight into these changes from an operational management perspective, as well as to test Thelen and Mahoney?s (2010) modes of institutional change. Consequently, the study researched implementations of an Investment Management System with a rules-based compliance module within financial organizations. The research consulted compliance and risk managers, as well as systems experts. The study suggests that prescriptive regulations are likely to create isomorphic configurations of rules-based compliance systems, which consequently will enable the institutionalization of associated compliance practices. The study reveals the ability of some agents within financial organizations to control the impact of regulatory institutions, not directly, but through the systems and processes they adopt to meet requirements. Furthermore, the research highlights the boundaries and relationships between each mode of change as future avenues of research.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We describe a fluorometric assay for heme synthetase, the enzyme that is genetically deficient in erythropoietic protoporphyria. The method, which can readily detect activity in 1 microliter of packed human lymphocytes, is based on the formation of zinc protoheme from protoporphyrin IX. That zinc chelatase and ferrochelatase activities reside in the same enzyme was shown by the competitive action of ferrous ions and the inhibitory effects of N-methyl protoporphyrin (a specific inhibitor of heme synthetase) on zinc chelatase. The Km for zinc was 11 micrograms and that for protoporphyrin IX was 6 microM. The Ki fro ferrous ions was 14 microM. Zinc chelatase was reduced to 15.3% of the mean control activity in lymphocytes obtained from patients with protoporphyria, thus confirming the defect of heme biosynthesis in this disorder. The assay should prove to be useful for determining heme synthetase in tissues with low specific activity and to investigate further the enzymatic defect in protoporphyria.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The financial crisis of 2007-2009 has precipitated large scale regulatory change. Tight deadlines for implementation require organizations to start working on remediation projects before final drafts of regulations are crystalized. Firms are faced with engaging in complex and costly change management programs at a time when profits are diminished. As a consequence of these factors, pre-crisis logics for organizing compliance practices are being questioned and new approaches introduced. Our study explores the use of Investment Management Systems (IMS) in facilitating compliance arrangements. Our motivation is to understand the new logics and the part played by IMS in supporting these approaches. The study adopts an institutional logics perspective to explore the use of such systems at eight financial organizations. The study found new logics for organizing compliance include consolidation, centralization, harmonization and consistency and that the IMS plays an important role in supporting and enabling related activities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Previously, governments have responded to the impacts of economic failures and consequently have developed more regulations to protect employees, customers, shareholders and the economic wellbeing of the state. Our research addresses how Accounting Information Systems (AIS) may act as carriers for institutionalised practices associated with maintaining regulatory compliance within the context of UK Asset Management Houses. The AIS was found to be a strong conduit for institutionalized compliance related practices, utilising symbolic systems, relational systems, routines and artefacts to carry approaches relating to regulative, normative and cultural-cognitive strands of institutionalism. Thus, AIS are integral to the development and dissipation of best practice for the management of regulatory compliance. As institutional elements are clearly present we argue that AIS and regulatory compliance provide a rich context to further institutionalism. Since AIS may act as conduits for regulatory approaches, both systems adopters and clients may benefit from actively seeking to codify and abstract best practices into AIS. However, the application of generic institutionalized approaches, which may be applied across similar organizations, must be tempered with each firm’s business environment and associated regulatory exposure. A balance should be sought between approaches specific enough to be useful but generic enough to be universally applied.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cholesterol is one of the key constituents for maintaining the cellular membrane and thus the integrity of the cell itself. In contrast high levels of cholesterol in the blood are known to be a major risk factor in the development of cardiovascular disease. We formulate a deterministic nonlinear ordinary differential equation model of the sterol regulatory element binding protein 2 (SREBP-2) cholesterol genetic regulatory pathway in an hepatocyte. The mathematical model includes a description of genetic transcription by SREBP-2 which is subsequently translated to mRNA leading to the formation of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), a main precursor of cholesterol synthesis. Cholesterol synthesis subsequently leads to the regulation of SREBP-2 via a negative feedback formulation. Parameterised with data from the literature, the model is used to understand how SREBP-2 transcription and regulation affects cellular cholesterol concentration. Model stability analysis shows that the only positive steady-state of the system exhibits purely oscillatory, damped oscillatory or monotic behaviour under certain parameter conditions. In light of our findings we postulate how cholesterol homestasis is maintained within the cell and the advantages of our model formulation are discussed with respect to other models of genetic regulation within the literature.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The incidence and severity of light leaf spot epidemics caused by the ascomycete fungus Pyrenopeziza brassicae on UK oilseed rape crops is increasing. The disease is currently controlled by a combination of host resistance, cultural practices and fungicide applications. We report decreases in sensitivities of modern UK P. brassicae isolates to the azole (imidazole and triazole) class of fungicides. By cloning and sequencing the P. brassicae CYP51 (PbCYP51) gene, encoding the azole target sterol 14α-demethylase, we identified two non-synonymous mutations encoding substitutions G460S and S508T associated with reduced azole sensitivity. We confirmed the impact of the encoded PbCYP51 changes on azole sensitivity and protein activity by heterologous expression in a Saccharomyces cerevisiae mutant YUG37::erg11 carrying a controllable promoter of native CYP51 expression. In addition, we identified insertions in the predicted regulatory regions of PbCYP51 in isolates with reduced azole sensitivity. The presence of these insertions was associated with enhanced transcription of PbCYP51 in response to sub-inhibitory concentrations of the azole fungicide tebuconazole. Genetic analysis of in vitro crosses of sensitive and resistant isolates confirmed the impact of PbCYP51 alterations in coding and regulatory sequences on a reduced sensitivity phenotype, as well as identifying a second major gene at another locus contributing to resistance in some isolates. The least sensitive field isolates carry combinations of upstream insertions and non-synonymous mutations, suggesting PbCYP51 evolution is on-going and the progressive decline in azole sensitivity of UK P. brassicae populations will continue. The implications for the future control of light leaf spot are discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The financial crisis of 2008 led to new international regulatory controls for the governance, risk and compliance of financial services firms. Information systems play a critical role here as political, functional and social pressures may lead to the deinstitutionalization of existing structures, processes and practices. This research examines how an investment management system is introduced by a leading IT vendor across eight client sites in the post-crisis era. Using institutional theory, it examines changes in working practices occurring at the environmental and organizational levels and the ways in which technological interventions are used to apply disciplinary effects in order to prevent inappropriate behaviors. The results extend the constructs of deinstitutionalization and identify empirical predictors for the deinstitutionalization of compliance and trading practices within financial organizations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose The research objective of this study is to understand how institutional changes to the EU regulatory landscape may affect corresponding institutionalized operational practices within financial organizations. Design/methodology/approach The study adopts an Investment Management System as its case and investigates different implementations of this system within eight financial organizations, predominantly focused on investment banking and asset management activities within capital markets. At the systems vendor site, senior systems consultants and client relationship managers were interviewed. Within the financial organizations, compliance, risk and systems experts were interviewed. Findings The study empirically tests modes of institutional change. Displacement and Layering were found to be the most prevalent modes. However, the study highlights how the outcomes of Displacement and Drift may be similar in effect as both modes may cause compliance gaps. The research highlights how changes in regulations may create gaps in systems and processes which, in the short term, need to be plugged by manual processes. Practical implications Vendors abilities to manage institutional change caused by Drift, Displacement, Layering and Conversion and their ability to efficiently and quickly translate institutional variables into structured systems has the power to ease the pain and cost of compliance as well as reducing the risk of breeches by reducing the need for interim manual systems. Originality/value The study makes a contribution by applying recent theoretical concepts of institutional change to the topic of regulatory change uses this analysis to provide insight into the effects of this new environment