4,414 research outputs found

    Off-line processing: reciprocal interactions between declarative and procedural memories

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    The acquisition of declarative (i.e., facts) and procedural (i.e., skills) memories may be supported by independent systems. This same organization may exist, after memory acquisition, when memories are processed off-line during consolidation. Alternatively, memory consolidation may be supported by interactive systems. This latter interactive organization predicts interference between declarative and procedural memories. Here, we show that procedural consolidation, expressed as an off-line motor skill improvement, can be blocked by declarative learning over wake, but not over a night of sleep. The extent of the blockade on procedural consolidation was correlated to participants' declarative word recall. Similarly, in another experiment, the reciprocal relationship was found: declarative consolidation was blocked by procedural learning over wake, but not over a night of sleep. The decrease in declarative recall was correlated to participants' procedural learning. These results challenge the concept of fixed independent memory systems; instead, they suggest a dynamic relationship, modulated by when consolidation takes place, allowing at times for a reciprocal interaction between memory systems

    The extension of liberalism beyond domestic boundaries : three problem cases

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    Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Linguistics and Philosophy, 1999.Includes bibliographical references (leaves 160-161).Liberalism, in any of its forms, places a strong emphasis on the individual-it prioritizes equal rights and liberties, and measures are taken to assure for all citizens the opportunity to make full use of their freedoms and entitlements. Many conceptions of human rights are objected to on the grounds that they are based on liberal premises, and insufficiently sensitive to the fact of reasonable cultural pluralism. Using as a foil recent work in this area by John Rawls, I argue in chapter one for a justificatory basis of human rights that advances values-in particular values of minimal democracy including the right to political participation-that may have emerged historically alongside liberalism but that we ought not consider specifically liberal. My account diverges form Rawls' at this point: he does not believe that such values can be defended from premises that are not specifically liberal. Since a group is, after all, a collection of individuals, liberalism appears to be committed, unsatisfactorily, to a permissive right to secede in the sense that, other things being equal, groups ought always to be permitted to secede voluntarily. I show in my second chapter that liberalism is not committed to this permissive view. Though liberalism implies that no one has a duty to refrain from secession, it does not support the stronger thesis that states must permit groups to secede if they wish. My treatment of secession argues for a more general framework in which those liberties whose protection is of basic importance to liberalism are distinguished from those whose protection is not so guaranteed. Derek Parfit has put forth a general difficulty regarding our obligations to future generations, to which I respond in chapter three. Parfit claims, plausibly, that we may suppose a major public policy decision to have sufficiently broad ramifications that in about two hundred years there would be nobody alive who would have been alive had some different policy been selected. But then the choice of such a policy would not make those people worse off, since they would not otherwise have been born. This would remain so even in the case of policies that cause the lives of future generations to be of a very low quality. Parfit's "Non-Identity Problem" challenges us to provide plausible moral reasons against pursuit of such public policies. I argue that the only adequate response to this problem comes from a liberal focus on the rights of future generations, and the moral status that this confers on them. Taking such seriously, many public polices can be shown to be objectionable despite the fact that they may not harm the interests of those affected by them.by Rachel Brown.Ph.D

    Feral Swine Disease Surveillance – National Targets and Pilot Projects

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    The National Feral Swine Damage Management Program (NFSP) in collaboration with the National Wildlife Disease Program (NWDP) and USDA APHIS Veterinary Services works to identify the diseases of national concern in feral swine. The current national disease surveillance program includes classical swine fever (CSF), swine brucellosis (SB), and pseudorabies (PRV). CSF is a foreign animal disease and feral swine samples collected and tested serve as part of Veterinary Services surveillance stream for this pathogen. Both SB and PRV have been eradicated from U.S. commercial swine operations; however, as they are endemic diseases in feral swine populations, monitoring of feral swine for SB and PRV is deemed important to inform the swine industry as well as other livestock entities of the potential risk of reintroduction. Wildlife Services routinely removes feral swine and collects serum (approximately 2,800 samples annually) to conduct serologic tests on these three diseases. Sampling is distributed over both space and time and is currently undertaken in 37 states of the U.S. with counties being ranked high, medium, and low priority based upon risk factors. In addition to the diseases of national concern, the NFSP supports a number of pilot projects to address disease issues that arise at a local level. In close collaboration with Wildlife Services field personnel and others on the ground, the NFSP is able to quickly and robustly identify and sample for additional pathogens of zoonotic, domestic livestock, or companion animal concern. These projects are often multi-agency collaborative efforts and include diseases such as bovine tuberculosis and chronic wasting disease

    Nitrogen budgeting for water quality improvement in pineapple production systems of south eastern Queensland, Australia.

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    The Glass House Mountains area was identified as a source of elevated nitrogen (N) which flows into the Pumicestone Passage and Moreton Bay. Elevated N causes decline in water quality and ecological function of these internationally important Ramsar wetlands, fisheries habitat, and recreational tourism natural amenities. Investigations into the origin of elevated aquatic N levels identified intensive horticultural activities were likely key contributors. A review of horticulture in the catchment was undertaken. The review determined that pineapple production systems in this area presented the largest opportunity for addressing aquatic N levels. Using a systems agronomy approach a partial N budget and review of nutrient management practices investigated nitrogen use efficiency (NUE). Findings identified N loading in waterways was impact by rainfall volume and frequency. Agronomic timing of N application to meet plant demand was imbalanced. Deep drainage is the predominant N loss pathway in major soil types of the catchment

    Staphylococcus aureus Colonization: Modulation of Host Immune Response and Impact on Human Vaccine Design

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    In apparent contrast to its invasive potential Staphylococcus aureus colonizes the anterior nares of 20–80% of the human population. The relationship between host and microbe appears particularly individualized and colonization status seems somehow predetermined. After decolonization, persistent carriers often become re-colonized with their prior S. aureus strain, whereas non-carriers resist experimental colonization. Efforts to identify factors facilitating colonization have thus far largely focused on the microorganism rather than on the human host. The host responds to S. aureus nasal colonization via local expression of anti-microbial peptides, lipids, and cytokines. Interplay with the co-existing microbiota also influences colonization and immune regulation. Transient or persistent S. aureus colonization induces specific systemic immune responses. Humoral responses are the most studied of these and little is known of cellular responses induced by colonization. Intriguingly, colonized patients who develop bacteremia may have a lower S. aureus-attributable mortality than their non-colonized counterparts. This could imply a staphylococcal-specific immune “priming” or immunomodulation occurring as a consequence of colonization and impacting on the outcome of infection. This has yet to be fully explored. An effective vaccine remains elusive. Anti-S. aureus vaccine strategies may need to drive both humoral and cellular immune responses to confer efficient protection. Understanding the influence of colonization on adaptive response is essential to intelligent vaccine design, and may determine the efficacy of vaccine-mediated immunity. Clinical trials should consider colonization status and the resulting impact of this on individual patient responses. We urgently need an increased appreciation of colonization and its modulation of host immunity

    Marketing authorization procedures for advanced cancer drugs: exploring the views of patients, oncologists, healthcare decision makers and citizens in France

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    International audienceBackground. The past decades have seen advances in cancer treatments in terms of toxicity and side effects but progress in the treatment of advanced cancer has been modest. New drugs have emerged improving progression free survival but with little impact on overall survival, raising questions about the criteria on which to base decisions to grant marketing authorizations and about the authorization procedure itself. For decisions to be fair, transparent and accountable, it is necessary to consider the views of those with relevant expertise and experience. Methods. We conducted a Q-study to explore the views of a range of stakeholders in France, involving: 54 patients (18 months after diagnosis); 50 members of the general population; 27 oncologists; 19 healthcare decision makers; and 2 individuals from the pharmaceutical industry. Results. Three viewpoints emerged, focussing on different dimensions entitled: 1) ‘Quality of life (QoL), opportunity cost and participative democracy’; 2)‘QoL and patient-centeredness’; and 3) ‘Length of life’. Respondents from all groups were associated with each viewpoint, except for healthcare decision makers, who were only associated with the first one. Conclusion. Our results highlight plurality in the views of stakeholders, emphasize the need for transparency in decision making processes, and illustrate the importance of a re-evaluation of treatments for all 3 viewpoints. In the context of advanced cancer, our results suggest that QoL should be more prominent amongst authorization criteria, as it is a concern for 2 of the 3 viewpoints

    Differential expression of microRNA-206 and its target genes in pre-eclampsia

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    Objectives: Pre-eclampsia is a multi-system disease that significantly contributes to maternal and fetal morbidity and mortality. In this study, we used a non-biased microarray approach to identify novel circulating miRNAs in maternal plasma that may be associated with pre-eclampsia. Methods: Plasma samples were obtained at 16 and 28 weeks of gestation from 18 women who later developed pre-eclampsia (cases) and 18 matched women with normotensive pregnancies (controls). We studied miRNA expression profiles in plasma and subsequently confirmed miRNA and target gene expression in placenta samples. Placental samples were obtained from an independent cohort of 19 women with pre-eclampsia matched with 19 women with normotensive pregnancies. Results: From the microarray, we identified 1 miRNA that was significantly differentially expressed between cases and controls at 16 weeks of gestation and 6 miRNAs that were significantly differentially expressed at 28 weeks. Following qPCR validation only one, miR-206, was found to be significantly increased in 28 week samples in women who later developed pre-eclampsia (1.4 fold change ± 0.2). The trend for increase in miR-206 expression was mirrored within placental tissue from women with pre-eclampsia. In parallel, IGF-1, a target gene of miR-206, was also found to be down-regulated (0.41 ± 0.04) in placental tissue from women with pre-eclampsia. miR-206 expression was also detectable in myometrium tissue and trophoblast cell lines. Conclusions: Our pilot study has identified miRNA-206 as a novel factor up-regulated in pre-eclampsia within the maternal circulation and in placental tissue

    The Weak Clustering of Gas-Rich Galaxies

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    We examine the clustering properties of HI-selected galaxies through an analysis of the HI Parkes All-Sky Survey Catalogue (HICAT) two-point correlation function. Various sub-samples are extracted from this catalogue to study the overall clustering of HI-rich galaxies and its dependence on luminosity, HI gas mass and rotational velocity. These samples cover the entire southern sky Dec < 0 deg, containing up to 4,174 galaxies over the radial velocity range 300-12,700 km/s. A scale length of r_0 = 3.45 +/- 0.25 Mpc/h and slope of gamma = 1.47 +/- 0.08 is obtained for the HI-rich galaxy real-space correlation function, making gas-rich galaxies among the most weakly clustered objects known. HI-selected galaxies also exhibit weaker clustering than optically selected galaxies of comparable luminosities. Good agreement is found between our results and those of synthetic HI-rich galaxy catalogues generated from the Millennium Run CDM simulation. Bisecting HICAT using different parameter cuts, clustering is found to depend most strongly on rotational velocity and luminosity, while the dependency on HI mass is marginal. Splitting the sample around v_rot = 108 km/s, a scale length of r_0 = 2.86 +/- 0.46 Mpc/h is found for galaxies with low rotational velocities compared to r_0 = 3.96 +/- 0.33 Mpc/h for the high rotational velocity sample.Comment: Accepted for publication in the Astrophysical Journa
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