814 resultados para Justin Trudeau
Resumo:
The cAMP-response element-binding protein (CREB)-binding protein and p300 are two highly conserved transcriptional coactivators and histone acetyltransferases that integrate signals from diverse signal transduction pathways in the nucleus and also link chromatin remodeling with transcription. In this report, we have examined the role of p300 in the control of the G1 phase of the cell cycle in nontransformed immortalized human breast epithelial cells (MCF10A) and fibroblasts (MSU) by using adenovirus vectors expressing p300-specific antisense sequences. Quiescent MCF10A and MSU cells expressing p300-specific antisense sequences synthesized p300 at much reduced levels and exited G1 phase without serum stimulation. These cells also showed an increase in cyclin A and cyclin A- and E-associated kinase activities characteristic of S phase induction. Further analysis of the p300-depleted quiescent MCF10A cells revealed a 5-fold induction of c-MYC and a 2-fold induction of c-JUN. A direct target of c-MYC, CAD, which is required for DNA synthesis, was also found to be up-regulated, indicating that up-regulation of c-MYC functionally contributed to DNA synthesis. Furthermore, S phase induction in p300-depleted cells was reversed when antisense c-MYC was expressed in these cells, indicating that up-regulation of c-MYC may directly contribute to S phase induction. Adenovirus E1A also induced DNA synthesis and increased the levels of c-MYC and c-JUN in serum-starved MCF10A cells in a p300-dependent manner. Our results suggest an important role of p300 in cell cycle regulation at G1 and raise the possibility that p300 may negatively regulate early response genes, including c-MYC and c-JUN, thereby preventing DNA synthesis in quiescent cells.
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Systemin-mediated defense signaling in tomato (Lycopersicon esculentum) plants is analogous to the cytokine-mediated inflammatory response in animals. Herein, we report that the initiation of defense signaling in suspension-cultured cells of Lycopersicon peruvianum by the peptide systemin, as well as by chitosan and β-glucan elicitor from Phytophtora megasperma, is inhibited by the polysulfonated naphtylurea compound suramin, a known inhibitor of cytokine and growth factor receptor interactions in animal cells. Using a radioreceptor assay, we show that suramin interfered with the binding of the systemin analog 125I-Tyr-2,Ala-15-systemin to the systemin receptor with an IC50 of 160 μM. Additionally, labeling of the systemin receptor with a photoaffinity analog of systemin was inhibited in the presence of suramin. Receptor-mediated tyrosine phosphorylation of a 48-kDa mitogen-activated protein kinase and alkalinization of the medium of suspension-cultured cells in response to systemin and carbohydrate elicitors were also inhibited by suramin. The inhibition of medium alkalinization by suramin was reversible in the presence of high concentrations of systemin and carbohydrate elicitors. Calyculin A and erythrosin B, intracellular inhibitors of phosphatases and plasma membrane proton ATPases, respectively, both induce medium alkalinization, but neither response was inhibited by suramin. The polysulfonated compound heparin did not inhibit systemin-induced medium alkalinization. NF 007, a suramin derivative, induced medium alkalinization, indicating that neither NF 007 nor heparin interact with elicitor receptors like suramin. The data indicate that cell-surface receptors in plants show some common structural features with animal cytokine and growth factor receptors that can interact with suramin to interfere with ligand binding.
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Afipia felis is a Gram-negative bacterium that causes some cases of human Cat Scratch Disease. A. felis can survive and multiply in several mammalian cell types, including macrophages, but the precise intracellular compartmentalization of A. felis-containing phagosomes is unknown. Here, we demonstrate that, in murine macrophages, most A. felis-containing phagosomes exclude lysosomal tracer loaded into macrophage lysosomes before, as well as endocytic tracer loaded after, establishment of an infection. Established Afipia-containing phagosomes possess neither early endosomal marker proteins [early endosome antigen 1 (EEA1), Rab5, transferrin receptor, trytophane aspartate containing coat protein (TACO)] nor late endosomal or lysosomal proteins [cathepsin D, β-glucuronidase, vacuolar proton-pumping ATPase, rab7, mannose-6-phosphate receptor, vesicle-associated membrane protein 8, lysosome-associated membrane proteins LAMP-1 and LAMP-2]. Those bacteria that will be found in a nonendosomal compartment enter the macrophage via an EEA1-negative compartment, which remains negative for LAMP-1. The smaller subpopulation of afipiae whose phagosomes will be part of the endocytic system enters into an EEA1-positive compartment, which also subsequently acquires LAMP-1. Killing of Afipia or opsonization with immune antibodies leads to a strong increase in the percentage of A. felis-containing phagosomes that interact with the endocytic system. We conclude that most phagosomes containing A. felis are disconnected from the endosome–lysosome continuum, that their unusual compartmentalization is decided at uptake, and that this compartmentalization requires bacterial viability.
Resumo:
In vivo pyruvate synthesis by malic enzyme (ME) and pyruvate kinase and in vivo malate synthesis by phosphoenolpyruvate carboxylase and the Krebs cycle were measured by 13C incorporation from [1-13C]glucose into glucose-6-phosphate, alanine, glutamate, aspartate, and malate. These metabolites were isolated from maize (Zea mays L.) root tips under aerobic and hypoxic conditions. 13C-Nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry were used to discern the positional isotopic distribution within each metabolite. This information was applied to a simple precursor-product model that enabled calculation of specific metabolic fluxes. In respiring root tips, ME was found to contribute only approximately 3% of the pyruvate synthesized, whereas pyruvate kinase contributed the balance. The activity of ME increased greater than 6-fold early in hypoxia, and then declined coincident with depletion of cytosolic malate and aspartate. We found that in respiring root tips, anaplerotic phosphoenolpyruvate carboxylase activity was high relative to ME, and therefore did not limit synthesis of pyruvate by ME. The significance of in vivo pyruvate synthesis by ME is discussed with respect to malate and pyruvate utilization by isolated mitochondria and intracellular pH regulation under hypoxia.
Resumo:
Service to the state is one of the core principles of the land-grant mission. This concept of service is also fundamental to a significant number of outreach activities in academic health sciences libraries, particularly those libraries affiliated with the public land-grant universities. The Dana Medical Library at the University of Vermont has a lengthy tradition of outreach to health care providers and health care consumers of the State of Vermont. Building on the foundation of the land-grant institution—which grew out of federal legislation introduced in the mid nineteenth century by Justin Morrill, Vermont's congressional representative—the Dana Medical Library has based its outreach activities on its dedication of service to the state in the promotion of healthy citizens through information dissemination in support of health care delivery. Reengineering library services designed to meet the specific information needs of its diverse clientele, partnering with disparate health care organizations, and relying on fees for service to expand its outreach activities, the Dana Medical Library has redefined the concept of health information outreach for the new millennium.
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Alternative reproductive cycles make use of different strategies to generate different reproductive products. In Escherichia coli, recA and several other rec genes are required for the generation of recombinant genomes during Hfr conjugation. During normal asexual reproduction, many of these same genes are needed to generate clonal products from UV-irradiated cells. However, unlike conjugation, this latter process also requires the function of the nucleotide excision repair genes. Following UV irradiation, the recovery of DNA replication requires uvrA and uvrC, as well as recA, recF, and recR. The rec genes appear to be required to protect and maintain replication forks that are arrested at DNA lesions, based on the extensive degradation of the nascent DNA that occurs in their absence. The products of the recJ and recQ genes process the blocked replication forks before the resumption of replication and may affect the fidelity of the recovery process. We discuss a model in which several rec gene products process replication forks arrested by DNA damage to facilitate the repair of the blocking DNA lesions by nucleotide excision repair, thereby allowing processive replication to resume with no need for strand exchanges or recombination. The poor survival of cellular populations that depend on recombinational pathways (compared with that in their excision repair proficient counterparts) suggests that at least some of the rec genes may be designed to function together with nucleotide excision repair in a common and predominant pathway by which cells faithfully recover replication and survive following UV-induced DNA damage.
Resumo:
Over the past decade, mindfulness practices have been used with increasing frequency as therapeutic components within cognitive behavioral treatment regimens. As is standard practice, prescriptive uses of mindfulness intervention are incorporated to improve end-state functioning by ameliorating problematic symptoms and conditions. Common change-targets include the control of cognitive and emotional content for purposes of enhancing psychological self-regulation and physical well-being. The term mindfulness applies to a heterogeneous range of practices, methods, and techniques. While there is no singular agreed upon definition for mindfulness, as a process concept, the term connotes an immediate, non-thetic access to events, wherein each occasioning event is experienced in toto within the broader contextual event-field, and distinct from intervening conceptual themes being noticed. Training in mindfulness practices may be conducted using individual, group, or small class formats. The current paper provides a meta-analytic review of 44 treatment outcome studies (extracted 1982 through 2006), which examines the clinical utility of mindfulness as the primary therapeutic approach. Results indicated that average effect sizes for mindfulness based interventions fell within the medium range for construct category variables examined (d = .56). These findings suggest that mindfulness training is a cost-effective treatment for a wide array of contemporary psychological problems and diagnoses, in addition to fostering positive psychology attributes such as quality and satisfaction with life. A critique of the research and recommendations for future research, including a need to examine the role of mindfulness as a tool for cultivating increased psychological acceptance and life satisfaction, is presented.
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Government actors create law against a backdrop of uncertainty. Limited information, unpredictable events, and lack of understanding interfere with accurately predicting a legal regime’s costs, benefits, and effects on other legal and social programs and institutions. Does the availability of no-fault divorce increase the number of terminated marriages? Will bulk-collection of telecommunications information about American citizens reveal terrorist plots? Can a sensitive species breed in the presence of oil and gas wells? The answers to these questions are far from clear, but lawmakers must act nonetheless. The problems posed by uncertainty cut across legal fields. Scholars and regulators in a variety of contexts recognize the importance of uncertainty, but no systematic, generally-applicable framework exists for determining how law should account for gaps in information. This Article suggests such a framework and develops a novel typology of strategies for accounting for uncertainty in governance. This typology includes “static law,” as well as three varieties of “dynamic law.” “Static law” is a legal rule initially intended to last in perpetuity. “Dynamic law” is intended to change, and includes: (1) durational regulation, or fixed legal rules with periodic opportunities for amendment or repeal; (2) adaptive regulation, or malleable legal rules with procedural mechanisms allowing rules to change; and (3) contingent regulation, or malleable legal rules with triggering mechanisms to substantively change to the rules. Each of these strategies, alone or in combination, may best address the uncertainty inherent in a particular lawmaking effort. This Article provides a diagnostic framework that lawmakers can use to identify optimal strategies. Ultimately, this approach to uncertainty yields immediate practical benefits by enabling lawmakers to better structure governance.
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This dissertation examines ancient historiographic citation methodologies in light of Mikhail Bakhtin’s dichotomy between polyphony and monologization. In particular, this dissertation argues that Eusebius of Caesarea’s Historia ecclesiastica (HE) abandons the monologic citation methodology typical of previous Greek and Hellenistic historiography and introduces a polyphonic citation methodology that influences subsequent late-ancient Christian historiography to varying degrees. Whereas Pre-Eusebian Greek and Hellenistic historiographers typically use citations to support the single authorial consciousness of the historiographer, Eusebius uses citations to counterbalance his own shortcomings as a witness to past events. Eusebius allows his citations to retain their own voice, even when they conflict with his. The result is a narrative that transcends the point of view of any single individual and makes multiple witnesses, including the narrator, available to the reader. Post-Eusebian late-ancient Christian historiographers exhibit the influence of Eusebius’ innovation, but they are not as intentional as Eusebius in their use of citation methodologies. Many subsequent Christian historiographers use both monologic and polyphonic citation methodologies. Their tendency to follow Eusebius’ practice of citing numerous lengthy citations sometimes emphasizes points of view that oppose the author’s point of view. When an opposing viewpoint surfaces in enough citations, a polyphonic citation methodology emerges. The reader holds the two different narrative strands in tension as the author continues to give voice to opposing viewpoints. After illustrating the citation methodologies with passages from numerous Greek, Hellenistic, and late ancient Christian historiographers, this dissertation concludes with a short computational analysis that uses natural language processing to reveal some broad trends that highlight the previous findings and suggest a possibility for future research.
Resumo:
Professor Robert J. Smith encourages readers, lawyers, and courts to forget Furman v. Georgia and to focus instead on death penalty challenges grounded in the diminished culpability of nearly all capital defendants. We applaud Professor Smith’s call to focus on the mental and emotional characteristics that reduce the blameworthiness of so many of those charged with capital crimes; recognizing diminished culpability as the rule rather than the exception among capital defendants conveys a reality that rarely finds its way into reported cases. We are troubled, however, by Professor Smith’s call to “forget Furman.” We believe the title and the article’s efforts to undermine Furman-based challenges disserve Professor Smith’s principal goal — addressing the United States’ broken death penalty system.
Resumo:
This Article demonstrates through original statistical research that prosecutors in Colorado were more likely to seek the death penalty against minority defendants than against white defendants. Moreover, defendants in Colorado’s Eighteenth Judicial District were more likely to face a death prosecution than defendants elsewhere in the state. Our empirical analysis demonstrates that even when one controls for the differential rates at which different groups commit statutorily death-eligible murders, non-white defendants and defendants in the Eighteenth Judicial District were still more likely than others to face a death penalty prosecution. Even when the heinousness of the crime is accounted for, the race of the accused and the place of the crime are statistically significant predictors of whether prosecutors will seek the death penalty. We discuss the implications of this disparate impact on the constitutionality of Colorado’s death penalty regime, concluding that the Colorado statute does not meet the dictates of the Eighth Amendment to the Constitution.
Resumo:
Recently the Supreme Court has placed new limits on both the substance of the Fourth Amendment and the exclusionary that serves as the principal remedy for Fourth Amendment violations. In this Article we briefly summarize these limitations and then argue that the curtailment of the exclusionary rule has the potential to ameliorate substantive Fourth Amendment doctrine. The limited reach of the modern exclusionary rule provides the Court with license to develop an expansive new substantive framework free of the specter of a correspondingly expansive remedial framework. One point on which nearly all jurists and commentators agree is that current Fourth Amendment doctrine is a mess. We argue that the Court’s exclusionary rule cases, while frustrating and ill-conceived if viewed in isolation, provide the Court with an opportunity to revisit problematic Fourth Amendment doctrine that was born under a very different remedial regime. Such an approach would allow the Court to adhere to its current view of the exclusionary rule as a remedy of last resort while creating a Fourth Amendment with teeth. The goal is a Fourth Amendment right that is more substantial and clearly defined, but a remedy that remains limited to egregious violations of clear substantive rules. The time is now to lift the Fourth Amendment fog.
Resumo:
Lying has a complicated relationship with the First Amendment. It is beyond question that some lies – such as perjury or pretending to be a police officer – are not covered by the First Amendment. But it is equally clear that some lies, even intentionally lying about military honors, are entitled to First Amendment protection. U.S. v. Alvarez, 132 S. Ct. 2537 (2012). To date, however, both Supreme Court doctrine and academic commentary has taken for granted that any constitutional protection for lies is purely prophylactic – it protects the liar to avoid chilling truthful speech. This Article is the first to argue, contrary to conventional wisdom, that certain types of lies paradoxically advance the values underlying the First Amendment. Our framework is descriptively novel and doctrinally important insofar as we provide the first comprehensive post-Alvarez look at the wide range of lies that may raise First Amendment issues. Because there was no majority opinion in Alvarez, there is uncertainty about which standard of constitutional scrutiny should apply to protected lies, an issue we examine at length. Moreover, our normative claim is straightforward: when a lie has intrinsic or instrumental value it should be treated differently from other types of lies and warrant the greatest constitutional protection. Specifically, we argue that investigative deceptions – lies used to secure truthful factual information about matters of public concern – deserve the utmost constitutional protection because they advance the underling purposes of free speech: they enhance political discourse, help reveal the truth, and promote individual autonomy. A prototypical investigative deception is the sort of misrepresentation required in order for an undercover journalist, investigator, or activist to gain access to information or images of great political significance that would not be available if the investigator disclosed her reporting or political objectives. Tactical use of such lies have a long history in American journalism and activism, from Upton Sinclair to his modern day heirs. Using the proliferation of anti-whistleblower statutes like Ag Gag laws as an illustrative example, we argue that investigative deceptions are a category of high value lies that ought to receive rigorous protection under the First Amendment. At the same time, we recognize that not all lies are alike and that in other areas, the government regulation of lies serves legitimate interests. We therefore conclude the Article by drawing some limiting principles to our theory.