Habit Formation and Fiscal Transmission in Open Economies

In this paper we analyze the ability of an open economy version of the neoclassical model to account for the time-series evidence on fiscal policy transmission. In a first step, we identify government spending shocks within a vector autoregression model. We find that i) government spending increases output and induces a simultaneous decline of investment and the current account, but does not affect consumption; ii) the responses of output and investment are smaller in more open economies, while current account deficits tend to be larger. We find the predictions of the model to be broadly in line with the evidence, once we allow for habit formation in consumption. Specifically, habits are crucial for government spending to induce a simultaneous decline in investment and the current account.Investment; Current Account; Habit Formation; Fiscal Policy.

Quantum vacuum photon-modes and superhydrophobicity

Nanostructures are commonly used for developing superhydrophobic surfaces. However, available wetting theoretical models ignore the effect of vacuum photon-modes alteration on van der Waals forces and thus on hydrophobicity. Using first-principle calculations, we show that superhydrophibicity of nanostructured surfaces is dramatically enhanced by vacuum photon-modes tuning. As a case study, wetting contact angles of a water droplet above a polyethylene nanostructured surface are obtained from the interaction potential energy calculated as function of the droplet-surface separation distance. This new approach could pave the way for the design of novel superhydrophobic coatings.Comment: 5 pages, 4 figures, final version published in Physical Review Letter

Effects of the vasoactive intestinal peptide (VIP) and related peptides on glioblastoma cell growth in vitro

The growth rate of numerous cancer cell lines is regulated in part by actions of neuropeptides of the vasoactive intestinal peptide (VIP) family, which also includes pituitary adenylate cyclase-activating peptide (PACAP), glucagon, and peptide histidine/isoleucine (PHI). The aim of this work was to investigate the effect of these peptides on the growth of the rat glioblastoma cell line C6 in vitro. We also sought to determine which binding sites were correlated with the effects observed. Proliferation studies performed by means of a CyQuant trade mark assay showed that VIP and PACAP strongly stimulated C6 cell proliferation at most of the concentrations tested, whereas PHI increased cell proliferation only when associated with VIP. Two growth hormone-releasing factor (GRF) derivatives and the VIP antagonist hybrid peptide neurotensin-VIP were able to inhibit VIP-induced cell growth stimulation, even at very low concentrations. Binding experiments carried out on intact cultured C6 cells, using 125I-labeled VIP and PACAP as tracers, revealed that the effects of the peptides on cell growth were correlated with the expression on C6 cells of polyvalent high-affinity VIP-PACAP binding sites and of a second subtype corresponding to very high-affinity VIP-selective binding species. The latter subtype, which interacted poorly with PACAP with a 10,000-fold lower affinity than VIP, might mediate the antagonist effects of neurotensin- VIP and of both GRF derivatives on VIP-induced cell growth stimulation

Habit Formation and Fiscal Transmission in Open Economies

In this paper we analyze the ability of an open economy version of the neoclassical model to account for the time-series evidence on fiscal policy transmission. In a first step, we identify government spending shocks within a vector autoregression model. We find that i) government spending increases output and induces a simultaneous decline of investment and the current account, but does not affect consumption; ii) the responses of output and investment are smaller in more open economies, while current account deficits tend to be larger. We find the predictions of the model to be broadly in line with the evidence, once we allow for habit formation in consumption. Specifically, habits are crucial for government spending to induce a simultaneous decline in investment and the current account

Brain delivery of vasoactive intestinal peptide (VIP) following nasal administration to rats

The aim of this work was to study in rats the nasal route for the brain delivery of the vasoactive intestinal peptide (VIP) neuropeptide. After evaluating VIP stability in solutions obtained from nasal washes, the effect of formulation parameters (pH 4-9, 0-1% (w/v) lauroylcarnitine (LC), hypo- or isoosmolality) on the brain uptake of intranasally administered VIP (10(-8)M)/125I-VIP (300,000 cpm/ml) was studied, using an in situ perfusion technique. Brain radioactivity distribution was assessed by quantitative autoradiographic analysis. Results were compared to intravenously administered VIP. With a hypotonic formulation at pH 4 containing 0.1% LC and 1% bovine serum albumin, VIP stability was satisfactory and loss by adsorption was minimal. Using this formulation, around 0.11% of initial radioactivity was found in the brain after 30 min perfusion and was located in the olfactory bulbs, the midbrain and the cerebellum. HPLC analysis of brain and blood extracts demonstrated the presence of intact VIP in brain and its complete degradation in the blood compartment. By intravenous administration, no intact VIP was found either in brain or in blood. In conclusion, intact VIP could be delivered successfully to the brain using the intranasal route for administration

Flot de conception automatique pour circuits commutables

National audienceLes FPGA, ou puces reconfigurables, n’ont pas cessé d’évoluer depuis leur création et sont désormais utilisés dans des systèmes complets (Xilinx Zynq ou Altera Stratix). Malgré tout, il reste de nombreux champs applicatifs desquels ils sont absents, et à tort. Utiliser les FPGA de manière plus intense au sein de systèmes complets est possible, mais il faut pour cela développer les capacités multi-utilisateurs de ces plateformes. Donner la capacité à une application s’exécutant sur un FPGA de se stopper pour, par exemple, laisser s’exécuter d’autres applications jugées prioritaires est particulièrement intéressant. Une telle action est qualifiée de « changement de contexte » (en anglais context-switch).Dans cet article, nous présentons une méthode et un outil permettant de donner cette capacité à des circuits fonctionnant sur cible reconfigurable. Le flot de conception présenté s’appuie sur un logiciel de synthèse de haut niveau et offre automatiquement la capacité de commutation aux circuits synthétisés. Les expériences menées sur un panel de circuits classiques montrent que l’ajout de cette capacité à un coût relativement faible ainsi qu’une rapidité de commutation sans égale dans la littérature

Automatic High-Level Hardware Checkpoint Selection for Reconfigurable Systems

International audience—Modern FPGAs provide great computational power and flexibility but there is still room for improving their performances. For example multiuser approaches are particularly underdeveloped as they require specific mechanisms still to be automated. Sharing an FPGA resource between applications or users requires a context switch ability. The latter enables pausing and resuming applications at system demand. This paper presents a method that automatically selects a good execution point, called hardware checkpoint, to perform a context switch on an FPGA. The method relies on a static analysis of the finite state machine of a circuit to select the checkpoint states. The obtained selection ensures that the context switch mechanism respects a given latency and tries to minimize the mechanism costs. The method takes advantage of its integration in an open-source HLS tool and preliminary results highlight its efficiency. Index Terms—FPGA, HLS, CAD, hardware context switc

Anticancer drug delivery with transferrin targeted polymeric chitosan vesicles

The study reports the initial biological evaluation of targeted polymeric glycol chitosan vesicles as carrier systems for doxorubicin (Dox). Transferrin (Tf) was covalently bound to the Dox-loaded palmitoylated glycol chitosan (GCP) vesicles using dimethylsuberimidate (DMSI). For comparison, glucose targeted niosomes were prepared using N-palmitoyl glucosamine. Biological properties were studied using confocal microscopy, flow cytometry, and cytotoxicity assays as well as a mouse xenograft model. Tf vesicles were taken up rapidly with a plateau after 1-2 h and Dox reached the nucleus after 60-90 min. Uptake was not increased with the use of glucose ligands, but higher uptake and increased cytotoxicity were observed for Tf targeted as compared to GCP Dox alone. In the drug-resistant A2780AD cells and in A431 cells, the relative increase in activity was significantly higher for the Tf-GCP vesicles than would have been expected from the uptake studies. All vesicle formulations had a superior in vivo safety profile compared to the free drug. The in vitro advantage of targeted Tf vesicles did not translate into a therapeutic advantage in vivo. All vesicles reduced tumor size on day 2 but were overall less active than the free drug

Wetting Transition on Hydrophobic Surfaces Covered by Polyelectrolyte Brushes

International audienceWe study the wetting by water of complex “hydrophobic-hydrophilic” surfaces made of a hydrophobic substrate covered by a hydrophilic polymer brush. Polystyrene (PS) substrates covered with polystyrene-block-poly(acrylic acid) PS-b-PAA diblock copolymer layers were fabricated by Langmuir-Schaefer depositions and analyzed by atomic force microscopy (AFM) and ellipsometry. On bare PS substrate, we measured advancing angles θA ) 93 ( 1° and receding angles θR ) 81 ( 1°. On PS covered with poorly anchored PS-b-PAA layers, we observed large contact angle hysteresis, θA ≈ 90° and θR ≈ 0°, that we attributed to nanometric scale dewetting of the PS-b-PAA layers. On well-anchored PS-b-PAA layers that form homogeneous PAA brushes, a wetting transition from partial to total wetting occurs versus the amount deposited: both θA and θR decrease close to zero. A model is proposed, based on the Young-Dupre´ equation, that takes into account the interfacial pressure of the brush Π, which was determined experimentally, and the free energy of hydration of the polyelectrolyte monomers ΔGPAA hyd , which is the only fitting parameter. With ΔGPAA hyd ≈ -1300 J/mol, the model renders the wetting transition for all samples and explains why the wetting transition depends mainly on the average thickness of the brush and weakly on the length of PAA chains