919 resultados para Responsive


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This article examines the impact of financialisation on the income shares of the top 1% from 1990-2010, through a panel analysis of 14 OECD countries. Drawing together literatures stressing the dependence of income inequality on the structural bargaining power of capital relative to labour, and of the dependence of accumulation on underlying institutionalised modes of state regulation, it shows that financialisation has significantly enhanced top income shares net of underlying controls. Whilst the income shares of the top 1% appear responsive to variables typical of wider studies of personal income inequality, we emphasise distinctive mechanisms of top income growth linked to the rising dominance of financial instruments and actors, facilitated by a historically specific regulatory order. These conditions were key to the emergence of a state of ‘asymmetric bargaining’ which disproportionately enhanced the fortunes of the wealthy. Results thus emphasise the importance of class-biased power resources and underlying regulatory structures, as determinants both of income concentration and of the distribution of economic rewards beyond growth capacity alone.

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This book examines the first human colonization of Asia and particularly the tropical environments of Southeast Asia during the Upper Pleistocene. In studyexamining the unique character of the Asian archaeological record, it reassesses long-accepted propositions about the development of human ‘modernity.’ Ryan J. Rabett reveals an evolutionarily relationship between colonization, the challenges encountered during this process – especially in relation to climatic and environmental change – and the forms of behaviour that emerged. This book argues that human ‘modernity’ is not something achieved in the remote past in one part of the world, but rather is a diverse, flexible, responsive, and on-going process of adaptation, one that continues to this day.

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The majority of bacteria in the natural environment live within the confines of a biofilm. The Gram-positive bacterium Bacillus subtilis forms biofilms that exhibit a characteristic wrinkled morphology and a highly hydrophobic surface. A critical component in generating these properties is the protein BslA, which forms a coat across the surface of the sessile community. We recently reported the structure of BslA, and noted the presence of a large surface-exposed hydrophobic patch. Such surface patches are also observed in the class of surface-active proteins known as hydrophobins, and are thought to mediate their interfacial activity. However, although functionally related to the hydrophobins, BslA shares no sequence nor structural similarity, and here we show that the mechanism of action is also distinct. Specifically, our results suggest that the amino acids making up the large, surface-exposed hydrophobic cap in the crystal structure are shielded in aqueous solution by adopting a random coil conformation, enabling the protein to be soluble and monomeric. At an interface, these cap residues refold, inserting the hydrophobic side chains into the air or oil phase and forming a three-stranded β-sheet. This form then self-assembles into a well-ordered 2D rectangular lattice that stabilizes the interface. By replacing a hydrophobic leucine in the center of the cap with a positively charged lysine, we changed the energetics of adsorption and disrupted the formation of the 2D lattice. This limited structural metamorphosis represents a previously unidentified environmentally responsive mechanism for interfacial stabilization by proteins.

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UNLABELLED: Influenza A viruses counteract the cellular innate immune response at several steps, including blocking RIG I-dependent activation of interferon (IFN) transcription, interferon (IFN)-dependent upregulation of IFN-stimulated genes (ISGs), and the activity of various ISG products; the multifunctional NS1 protein is responsible for most of these activities. To determine the importance of other viral genes in the interplay between the virus and the host IFN response, we characterized populations and selected mutants of wild-type viruses selected by passage through non-IFN-responsive cells. We reasoned that, by allowing replication to occur in the absence of the selection pressure exerted by IFN, the virus could mutate at positions that would normally be restricted and could thus find new optimal sequence solutions. Deep sequencing of selected virus populations and individual virus mutants indicated that nonsynonymous mutations occurred at many phylogenetically conserved positions in nearly all virus genes. Most individual mutants selected for further characterization induced IFN and ISGs and were unable to counteract the effects of exogenous IFN, yet only one contained a mutation in NS1. The relevance of these mutations for the virus phenotype was verified by reverse genetics. Of note, several virus mutants expressing intact NS1 proteins exhibited alterations in the M1/M2 proteins and accumulated large amounts of deleted genomic RNAs but nonetheless replicated to high titers. This suggests that the overproduction of IFN inducers by these viruses can override NS1-mediated IFN modulation. Altogether, the results suggest that influenza viruses replicating in IFN-competent cells have tuned their complete genomes to evade the cellular innate immune system and that serial replication in non-IFN-responsive cells allows the virus to relax from these constraints and find a new genome consensus within its sequence space.

IMPORTANCE: In natural virus infections, the production of interferons leads to an antiviral state in cells that effectively limits virus replication. The interferon response places considerable selection pressure on viruses, and they have evolved a variety of ways to evade it. Although the influenza virus NS1 protein is a powerful interferon antagonist, the contributions of other viral genes to interferon evasion have not been well characterized. Here, we examined the effects of alleviating the selection pressure exerted by interferon by serially passaging influenza viruses in cells unable to respond to interferon. Viruses that grew to high titers had mutations at many normally conserved positions in nearly all genes and were not restricted to the NS1 gene. Our results demonstrate that influenza viruses have fine-tuned their entire genomes to evade the interferon response, and by removing interferon-mediated constraints, viruses can mutate at genome positions normally restricted by the interferon response.

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Surveys reveal that domestic abuse is more commonplace among teenagers and young adults than older populations, yet surprisingly little is written about young men’s involvement in it. Reporting on a three-year study based in the UK, this book explores young men’s involvement in domestic abuse, whether as victims, perpetrators or witnesses to violent behaviors between adults. Original survey data, focus group material and in-depth biographical interviews are used to make the case for a more thoroughgoing engagement with the meanings young men come to attribute to violent behavior, include the tendency among many to configure violence within families as "fights" that call for acts of male heroism. The book also highlights the dearth of services interventions for young men prone to domestic abuse, and the challenges of developing responsive practice in this area. Each section of the book highlights further online resources that those looking to conduct research in this area or apply its insights in practice can draw upon.

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The introduction of microarray technology to the scientific and medical communities has dramatically changed the way in which we now address basic biomedical questions. Expression profiling using microarrays facilitates an experimental approach where alterations in the transcript level of entire transcriptomes can be simultaneously assayed in response to defined stimuli. We have used microarray analysis to identify downstream transcriptional targets of the BRCA1 (Breast Cancer 1) tumour-suppressor gene as a means of defining its function. BRCA1 has been implicated in the predisposition to early onset breast and ovarian cancer and while its exact function remains to be defined, roles in DNA repair, cell-cycle control and transcriptional regulation have been implied. In the current study we have generated cell lines with tetracycline-regulated, inducible expression of BRCA1 as a tool to identify genes, which might represent important effectors of BRCA1 function. Oligonucleotide array-based expression profiling identified a number of genes that were upregulated at various times following inducible expression of BRCA1 including the DNA damage-responsive gene GADD45 (Growth Arrest after DNA Damage). Identified targets were confirmed by Northern blot analysis and their functional significance as BRCA1 targets examined.

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The characterization of complex cellular responses to diverse stimuli can be studied by the use of emerging chip-based technologies.

The p53 pathway is critical to maintaining the integrity of the genome in multicellular organisms. The p53gene is activated in response to DNA damage and encodes a transcription factor [1], which in turn activates genes that arrest cell growth and induce apoptosis, thereby preventing the propagation of genetically damaged cells. It is the most important known tumor suppressor gene: perhaps half of all human neoplasms have mutations in p53, and there is a remarkable concordance between oncogenic mutation and the loss of p53 transcriptional activity [2]. There is also compelling experimental evidence that loss of p53 function (by whatever means) is one of the key oncogenic steps in human cells, along with altered telomerase activity and expression of mutant ras [3]. So far, however, relatively few of the genes regulated by p53 have been identified and it is not even known how many binding sites there are for p53 in the genome, although an estimate based on the incidence of the canonical p53 consensus binding site (four palindromic copies of the sequence 5'-PuPuPuGA/T-3', where Pu is either purine) in a limited region suggests there may be as many as 200 to 300, possibly representing the same number of p53-responsive genes [4]. This makes the p53 response an attractive target for the emerging techniques for global analysis of gene expression, and two recent reports [5,6] illustrate the ways in which these techniques can be used to elucidate the spectrum of genes regulated by this key transcription factor. Vogelstein and colleagues [5] have used serial analysis of gene expression (SAGE) to identify 34 genes that exhibit at least a 10-fold upregulation in response to inducible expression of p53; Tanaka et al. [6] have used differential display to identify p53R2, a homolog of ribonuclease reductase small subunit (R2) as a target gene, thereby for the first time implicating p53 directly in the repair of DNA damage.

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The breast cancer susceptibility gene BRCA1 encodes a protein implicated in the cellular response to DNA damage, with postulated roles in homologous recombination as well as transcriptional regulation. To identify downstream target genes, we established cell lines with tightly regulated inducible expression of BRCA1. High-density oligonucleotide arrays were used to analyze gene expression profiles at various times following BRCA1 induction. A major BRCA1 target is the DNA damage-responsive gene GADD45. Induction of BRCA1 triggers apoptosis through activation of c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK), a signaling pathway potentially linked to GADD45 gene family members. The p53-independent induction of GADD45 by BRCA1 and its activation of JNK/SAPK suggest a pathway for BRCA1-induced apoptosis.

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Uptake kinetics of arsenate were determined in arsenate tolerant and non-tolerant clones of the grass Deschampsia cespitosa under differing root phosphorus status to investigate the mechanism controlling the suppression of arsenate influx observed in tolerant clones. Influx was always lower in tolerants compared to non-tolerants. Short term influx of arsenate by the high affinity uptake system in both tolerant clones was relatively insensitive to root phosphorus status. This was in contrast to the literature where the regulation of the phosphate (arsenate) uptake system is normally much more responsive to plant phosphorus status. The low affinity uptake system in both tolerant and non-tolerant clones, unlike the high affinity uptake system, was more closely regulated by root phosphate status and was repressed to a much greater degree under increasing root phosphorus levels than the high affinity system. © 1994 Kluwer Academic Publishers.

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Bovine TB (bTB) is endemic in Irish cattle and has eluded eradication despite considerable expenditure, amid debate over the relative roles of badgers and cattle in disease transmission. Using a comprehensive dataset from Northern Ireland (>10,000 km2; 29,513 cattle herds), we investigated interactions between host populations in one of the first large-scale risk factor analyses for new herd breakdowns to combine data on both species. Cattle risk factors (movements, international imports, bTB history, neighbours with bTB) were more strongly associated with herd risk than area-level measures of badger social group density, habitat suitability or persecution (sett disturbance). Highest risks were in areas of high badger social group density and high rates of persecution, potentially representing both responsive persecution of badgers in high cattle risk areas and effects of persecution on cattle bTB risk through badger social group disruption. Average badger persecution was associated with reduced cattle bTB risk (compared with high persecution areas), so persecution may contribute towards sustaining bTB hotspots; findings with important implications for existing and planned disease control programmes.

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The efficiency of solar-energy-conversion devices depends on the absorption region and intensity of the photon collectors. Organic chromophores, which have been widely stabilized on inorganic semiconductors for light trapping, are limited by the interface between the chromophore and semiconductor. Herein we report a novel orange zinc germanate (Zn-Ge-O) with a chromophore-like structure, by which the absorption region can be dramatically expanded. Structural characterizations and theoretical calculations together reveal that the origin of visible-light response can be attributed to the unusual metallic Ge-Ge bonds which act in a similar way to organic chromophores. Benefiting from the enhanced light harvest, the orange Zn-Ge-O demonstrates superior capacity for solar-driven hydrogen production.

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OBJECTIVE: The efficacy of docetaxel has recently been shown to be increased under hypoxic conditions through the down-regulation of hypoxia-inducible-factor 1α (HIF1A). Overexpression of the hypoxia-responsive gene class III β-tubulin (TUBB3) has been associated with docetaxel resistance in a number of cancer models. We propose that administration of docetaxel to prostate patients has the potential to reduce the hypoxic response through HIF1A down-regulation and that TUBB3 down-regulation participates in sensitivity to docetaxel.

METHODS: The cytotoxic effect of docetaxel was determined in both 22Rv1 and DU145 prostate cancer cell lines and correlated with HIF1A expression levels under aerobic and hypoxic conditions. Hypoxia-induced chemoresistance was investigated in a pair of isogenic docetaxel-resistant PC3 cell lines. Basal and hypoxia-induced TUBB3 gene expression levels were determined and correlated with methylation status at the HIF1A binding site.

RESULTS: Prostate cancer cells were sensitive to docetaxel under both aerobic and hypoxic conditions. Hypoxic cytotoxicity of docetaxel was consistent with a reduction in detected HIF1A levels. Sensitivity correlated with reduced basal and hypoxia-induced HIF1A and TUBB3 expression levels. The TUBB3 HIF1A binding site was hypermethylated in prostate cell lines and tumor specimens, which may exclude transcription factor binding and induction of TUBB3 expression. However, acquired docetaxel resistance was not associated with TUBB3 overexpression.

CONCLUSION: These data suggest that the hypoxic nature of a tumor may have relevance as regard to their response to docetaxel. Further investigation into the nature of this relationship may allow identification of novel targets to improve tumor control in prostate cancer patients.

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Hypoxia is an inevitable feature of solid tumors and a common cause of treatment failure. Hypoxia acts as a trigger to genetic instability, apoptosis and possibly metastases. The adaptive response to cellular hypoxia involves the modulation of the synthesis of multiple proteins controlling processes such as glucose homeostasis, angiogenesis, vascular permeability and inflammation. The hypoxia responsive element (HRE) sequences isolated from oxygen-responsive genes have been shown to selectively induce gene expression in response to hypoxia when placed upstream of a promoter. The levels of induced gene expression were dependent on the number of HRE copies and the oxygen tension. Hypoxia-mediated cancer gene therapy strategies may represent a promising mean to significantly improve the efficacy of standard radiation therapy and chemotherapy approaches.

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Significant evidence has accumulated indicating that certain genes are induced by ionising radiation. An implication of this observation is that their promoter regions include radiation-responsive sequences. These sequences have been isolated in the promoter of several genes including Erg-1, p21/WAF-1, GADD45alpha and t-PA. The mechanism by which radiation induces gene expression remains unclear but involves putative binding sites for selected transcription factors and/or p53. Consensus CC(A/T)6GG sequences have been localized in the Erg-1 promoter and are referred to as serum response elements or CArG elements. The tandem combination of CArG elements has been shown to improve gene expression levels, with a 9-copy motif conferring maximum inducibility. The response of these genes to ionising radiation appears to follow a sigmoid relationship with time and dose. Therapeutic induction of suicide genes and significant cytotoxicity can be achieved at clinically relevant x-rays doses both in vitro and in vivo but was found to be cell-type dependent. Radiation-inducible gene therapy can be potentially enhanced by exploiting hypoxia through the inclusion of hypoxia-response element motifs in the expression cassette, the use of the anaerobic bacteria or the use of neutron irradiation. These results are encouraging and provide significant evidence that gene therapy targeted to the radiation field is a reasonably attractive therapeutic option and could help overcome hypoxic radioresistant tumors.

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This chapter focuses on women’s imprisonment in the context of gendered punishment inflicted by the State. It considers the gender-specific consequences of incarceration for women prisoners and the potential of gender-responsive alternatives to custodial sentences. Following a brief historical overview, it traces the rise and consolidation of women’s incarceration in UK jurisdictions, noting the significance of devolution on the prison systems of Scotland and Northern Ireland. In examining the impact of neo-liberal policies and globalisation on women’s imprisonment, it draws comparisons with other advanced democratic states. Analysing the rationale underpinning the disproportionate rise in women’s incarceration, particularly in the UK and the USA the chapter identifies the persistent tensions between retributivism/ incapacitation and reformism/rehabilitation. Drawing on international research demonstrating the complex needs and vulnerabilities of women and girl prisoners, the chapter reveals the gendered harm experienced within penal regimes and the recent development - and limitations - of official gender-specific policies and practices. The emergence of distinct but related political discourses on ‘risk’ and ‘responsibilisation’ as applied to women in conflict with the law, and their consequent criminalisation, is critiqued in the contexts of structural disadvantage, gender discrimination and institutionalised racism. Within these oppressive dynamics often severe deprivations are inflicted on women’s acts of resistance both inside prison and in their communities post-release, further confining the potential of individual and collective agency. Finally, the chapter proposes fundamental change through establishing women-centred alternatives to prison, alongside policies committed to decarceration, while working towards securing the abolition of women’s imprisonment.