670 research outputs found

    Orienting versus inhibition in the concealed information test: different cognitive processes drive different physiological measures

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    The Concealed Information Test (CIT) provides a valid tool for psychophysiological detection of concealed knowledge. However, its precise theoretical underpinnings remain a matter of debate. The differential physiological responses elicited by concealed, relevant items, relative to control items, were traditionally explained as reflecting an orienting response (OR). According to an alternative account, these responses reflect attempts to inhibit arousal. The present study examined whether and to what extent CIT detection efficiency is affected by instructions aimed at manipulating arousal inhibition (AI). One hundred and forty-eight undergraduate students completed a CIT, while electrodermal, cardiac, and respiratory measures were recorded. Half of the participants were requested to imagine that they are suspected of committing a crime and were motivated to avoid detection (presumably eliciting both OR and AI), while the other half were requested to imagine that they are witnesses of a crime and were motivated to be detected (presumably eliciting OR only). All participants were further requested to remain silent throughout the test. In both conditions, concealed items led to a similar increase in skin conductance as compared to the control items. However, the typically observed heart rate deceleration and respiratory suppression were found in suspects, but not in witnesses. These data imply that different mechanisms drive the responding of different psychophysiological measures used in the CIT, with skin conductance reflecting OR, and heart rate and respiration primarily reflecting AI

    Stepwise Adsorption of Alkoxy-Pyrene Derivatives onto a Lamellar, Non-Porous Naphthalenediimide-Template on HOPG

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    The development of new strategies for the preparation of multicomponent supramolecular assemblies is a major challenge on the road to complex functional molecular systems. Here we present the use of a non-porous self-assembled monolayer from uC33-NDI-uC33, a naphthalenediimide symmetrically functionalized with unsaturated 33 carbon-atom-chains, to prepare bicomponent supramolecular surface systems with a series of alkoxy-pyrene (PyrOR) derivatives at the liquid/HOPG interface. While previous attempts at directly depositing many of these PyrOR units at the liquid/HOPG interface failed, the multicomponent approach through the uC33-NDI-uC33 template enabled control over molecular interactions and facilitated adsorption. The PyrOR deposition restructured the initial uC33-NDI-uC33 monolayer, causing an expansion in two dimensions to accommodate the guests. As far as we know, this represents the first example of a non-porous or non-metal complex-bearing monolayer that allows the stepwise formation of multicomponent supramolecular architectures on surfaces

    Theory of Lipid Polymorphism: Application to Phosphatidylethanolamine and Phosphatidylserine

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    We introduce a microscopic model of a lipid with a charged headgroup and flexible hydrophobic tails, a neutral solvent, and counter ions. Short-ranged interactions between hydrophilic and hydrophobic moieties are included as are the Coulomb interactions between charges. Further, we include a short-ranged interaction between charges and neutral solvent, which mimics the short-ranged, thermally averaged interaction between charges and water dipoles. We show that the model of the uncharged lipid displays the usual lyotropic phases as a function of the relative volume fraction of the headgroup. Choosing model parameters appropriate to dioleoylphosphatidylethanolamine in water, we obtain phase behavior which agrees well with experiment. Finally we choose a solvent concentration and temperature at which the uncharged lipid exhibits an inverted hexagonal phase and turn on the headgroup charge. The lipid system makes a transition from the inverted hexagonal to the lamellar phase which is related to the increased waters of hydration correlated with the increased headgroup charge via the charge-solvent interaction. The polymorphism displayed upon variation of pH mimics that of the behavior of phosphatidylserine.Comment: Submitte

    Engineering long-range order in supramolecular assemblies on surfaces : the paramount role of internal double bonds in discrete long-chain naphthalenediimides

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    Achieving long-range order with surface-supported supramolecular assemblies is one of the pressing challenges in the prospering field of non-covalent surface functionalization. Having access to defect-free on-surface molecular assemblies will pave the way for various nanotechnology applications. Here we report the synthesis of two libraries of naphthalenediimides (NDIs) symmetrically functionalized with long aliphatic chains (C28 and C33) and their self-assembly at the 1-phenyloctane/highly oriented pyrolytic graphite (1-PO/HOPG) interface. The two NDI libraries differ by the presence/absence of an internal double bond in each aliphatic chain (unsaturated and saturated compounds, respectively). All molecules assemble into lamellar arrangements, with the NDI cores lying flat and forming 1D rows on the surface, while the carbon chains separate the 1D rows from each other. Importantly, the presence of the unsaturation plays a dominant role in the arrangement of the aliphatic chains, as it exclusively favors interdigitation. The fully saturated tails, instead, self-assemble into a combination of either interdigitated or non-interdigitated diagonal arrangements. This difference in packing is spectacularly amplified at the whole surface level and results in almost defect-free self-assembled monolayers for the unsaturated compounds. In contrast, the monolayers of the saturated counterparts are globally disordered, even though they locally preserve the lamellar arrangements. The experimental observations are supported by computational studies and are rationalized in terms of stronger van der Waals interactions in the case of the unsaturated compounds. Our investigation reveals the paramount role played by internal double bonds on the self-assembly of discrete large molecules at the liquid/solid interface

    Report Topsector Potato India and Ethiopia 2015/16

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    The Agricultural Counsellor of the Netherlands Embassy in Delhi initiated a BOCI project ‘Overview of the potato chain in India’ in early 2011. In September 2012 this initiative has been adopted by the Dutch and Indian stakeholders and the Pubic Private Partnership (PPS) was established to facilitate the intensification of collaboration between Dutch and Indian stakeholders of the potato chain. A team of Wageningen UR researchers was commissioned to carry out this project. In 2011, the team collected information from reports, personal files, internet and some Dutch companies and reported the information in “An overview of the potato sector in India and prospects of Indo & Dutch cooperation”. The team also participated in the Netherlands Trade mission to India (5 & 11 June 2011) and visited the Central Potato Research Institute at Shimla. Furthermore jointly with the Agricultural Counsellor we organized a potato seminar to present our findings on 5 October 2011 in Delhi. Major potato stakeholders both from India and from the Netherlands attended the seminar; total number of participants was about 60 persons. In 2012, 2013, 2014, 2015 and 2016 the team carried out different tasks such as presenting information on various subjects of the Dutch and Indian potato chain to exchange knowledge. In addition, several identified subjects were investigated. All actions and activities aimed to facilitate collaboration between Dutch and Indian stakeholders. Visits to different locations of India accompanied by Dutch stakeholders, meetings with experts of the Indian potato production chain both stakeholders and researchers, and topics such as skin curing and chemical haulm killing, reduce storage losses and the establishment of the Centres of Excellence (CoE) in Punjab (Jalandhar) and Uttar Pradesh, and the Centre of Potato Expertise (COPE) at Ludhiana (Punjab) were successfully accomplished
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