344 research outputs found

    Are Subjects Making Financial Decisions in Lab Auctions or Are They Just Gambling?

    Get PDF
    Optimal bidding strategies in first-price and Dutch auctions are theoretically isomorphic but depend on bidder risk attitudes. However, laboratory experiments consistently find different behaviour between auction formats. This article explores whether the notion in psychology that financial and gambling risks are viewed differently can explain the discrepancy. Ultimately, the evidence does not support this hypothesis, but a bidder\u27s propensity to gamble is associated with how much risk he takes in both auctions whereas his propensity to take financial risks is not. The results suggest that subjects may view themselves as gambling in laboratory auctions rather than making financial decisions

    Role of shear stress and tPA concentration in the fibrinolytic potential of thrombi

    Get PDF
    Funding: This research was funded by British Heart Foundation PG/08/127/26517 awarded to N.A.B. and D.E.N. C.S.W. and N.J.M. were supported by the British Heart Foundation project grants (PG/15/82/31721 and PG/20/17/35050). D.E.N. and A.J.L. were supported by the British Heart Foundation project grant PG/04/131/18118. D.E.N. is supported by the British Heart Foundation (CH/09/002, RE/18/5/34216, RG/16/10/32375) and is the recipient of a Wellcome Trust Senior Investigator Award (WT103782AIA).Peer reviewedPublisher PD

    Efficient Design and Analysis of Lightweight Reinforced Core Sandwich and PRSEUS Structures

    Get PDF
    Design, analysis, and sizing methods for two novel structural panel concepts have been developed and incorporated into the HyperSizer Structural Sizing Software. Reinforced Core Sandwich (RCS) panels consist of a foam core with reinforcing composite webs connecting composite facesheets. Boeing s Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) panels use a pultruded unidirectional composite rod to provide axial stiffness along with integrated transverse frames and stitching. Both of these structural concepts are ovencured and have shown great promise applications in lightweight structures, but have suffered from the lack of efficient sizing capabilities similar to those that exist for honeycomb sandwich, foam sandwich, hat stiffened, and other, more traditional concepts. Now, with accurate design methods for RCS and PRSEUS panels available in HyperSizer, these concepts can be traded and used in designs as is done with the more traditional structural concepts. The methods developed to enable sizing of RCS and PRSEUS are outlined, as are results showing the validity and utility of the methods. Applications include several large NASA heavy lift launch vehicle structures

    Energy Trends: September 2020

    Get PDF
    Energy Trends and Energy Prices are produced by the Department for Business, Energy and Industrial Strategy (BEIS) on a quarterly basis. Both periodicals are published concurrently in June, September, December and March. The September editions cover the second quarter of the current year

    Analysis of Nigerians with Apparently Sporadic Parkinson Disease for Mutations in LRRK2, PRKN and ATXN3

    Get PDF
    Several genetic variations have been associated with Parkinson disease in different populations over the past few years. Although a considerable number of worldwide populations have been screened for these variants, results from Sub-Saharan populations are very scarce in the literature. In the present report we have screened a cohort of Parkinson disease patients (n = 57) and healthy controls (n = 51) from Nigeria for mutations in the genes PRKN, LRRK2 and ATXN3. No pathogenic mutations were found in any of the genes. Hence, common pathogenic mutations in these genes, observed in several different populations, are not a frequent cause of Parkinson disease in Nigeria

    Rationality, Irrationality and Escalating Behavior in Lowest Unique Bid Auctions

    Get PDF
    Information technology has revolutionized the traditional structure of markets. The removal of geographical and time constraints has fostered the growth of online auction markets, which now include millions of economic agents worldwide and annual transaction volumes in the billions of dollars. Here, we analyze bid histories of a little studied type of online auctions – lowest unique bid auctions. Similarly to what has been reported for foraging animals searching for scarce food, we find that agents adopt Lévy flight search strategies in their exploration of “bid space”. The Lévy regime, which is characterized by a power-law decaying probability distribution of step lengths, holds over nearly three orders of magnitude. We develop a quantitative model for lowest unique bid online auctions that reveals that agents use nearly optimal bidding strategies. However, agents participating in these auctions do not optimize their financial gain. Indeed, as long as there are many auction participants, a rational profit optimizing agent would choose not to participate in these auction markets

    Significance of the parkin and PINK1 gene in Jordanian families with incidences of young-onset and juvenile parkinsonism

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Parkinson's disease is a progressive neurodegenerative disorder, where most cases are sporadic with a late onset. In rare incidences familial forms of early-onset parkinsonism occur, and when recessively inherited, cases are often explained by mutations in either the <it>parkin </it>(PARK2) or <it>PINK1 </it>(PARK6) gene or on exceptional occasions the <it>DJ-1 </it>(PARK7) or <it>ATP13A2 </it>(PARK9) gene. Recessively inherited deletions/duplications and point mutations in the <it>parkin </it>gene are the most common cause of early-onset parkinsonism known so far, but in an increasing number of studies, genetic variations in the serine/threonine kinase domain of the <it>PINK1 </it>gene are found to explain early-onset parkinsonism.</p> <p>Methods</p> <p>In this study all families were from a population with a high incidence of consanguinity. We investigated 11 consanguineous families comprising 17 affected with recessively inherited young-onset parkinsonism for mutations both in the <it>parkin </it>and <it>PINK1 </it>gene. Exons and flanking regions were sequenced, and segregation patterns of genetic variation were assessed in members of the respective families. An exon dosage analysis was performed for all exons in both genes.</p> <p>Results</p> <p>In the <it>parkin </it>gene, a three generation family was identified with an exon 4 deletion segregating with disease. Both affected were homozygous for the deletion that segregated on a haplotype that spanned the gene in a haplotype segregation analysis that was performed using additional markers. Exon dosage analysis confirmed the recessive pattern of inheritance with heterozygous deletions segregating in healthy family members. In the <it>PINK1 </it>gene we identified two novel putative pathogenic substitutions, P416R and S419P, located in a conserved motif of the serine/threonine kinase domain. Both substitutions segregated with disease in agreement with a recessive pattern of inheritance within respective families and both were present as homozygous in two affected each. We also discuss common polymorphisms in the two genes found to be co-segregating within families.</p> <p>Conclusion</p> <p>Our results further extend on the involvement of <it>PINK1 </it>mutations in recessive early-onset parkinsonism with clinical features similar to carriers of <it>parkin </it>mutations.</p

    Dopamine-Induced Conformational Changes in Alpha-Synuclein

    Get PDF
    Background: Oligomerization and aggregation of α-synuclein molecules play a major role in neuronal dysfunction and loss in Parkinson's disease [1]. However, α-synuclein oligomerization and aggregation have mostly been detected indirectly in cells using detergent extraction methods [2], [3], [4]. A number of in vitro studies showed that dopamine can modulate the aggregation of α-synuclein by inhibiting the formation of or by disaggregating amyloid fibrils [5], [6], [7]. Methodology/Principal Findings: Here, we show that α-synuclein adopts a variety of conformations in primary neuronal cultures using fluorescence lifetime imaging microscopy (FLIM). Importantly, we found that dopamine, but not dopamine agonists, induced conformational changes in α-synuclein which could be prevented by blocking dopamine transport into the cell. Dopamine also induced conformational changes in α-synuclein expressed in neuronal cell lines, and these changes were also associated with alterations in oligomeric/aggregated species. Conclusion/Significance: Our results show, for the first time, a direct effect of dopamine on the conformation of α-synuclein in neurons, which may help explain the increased vulnerability of dopaminergic neurons in Parkinson's disease
    corecore