Does discussion lead to opinion change? An experiment in deliberative democracy

While the model of deliberative democracy gives a crucial role to dialogue, empirical evidence has not yet established if discussion helps to reach a better understanding of political issues and, above all, if individuals are prepared to change their views and preferences. This article presents an experiment carried out within the Department of Political and Social Sciences at the LUISS University of Rome. Students were asked to discuss in the classroom the course issues, and to cast a vote on selected issues before and after the deliberation. Although our sample is not representative, we have managed to gather evidences from the same population on a rather large number of issues. Students changed their view in 25.5 per cent of cases, they agreed that discussion increased their understanding of the various issues, while students with strong ex-ante views are more reluctant to change their opinions as a consequence of discussion. The experiment also shows the presence of impermeable and permeable subjects, the former which are more refractory to the discussion in changing their opinion, while the latter are more likely to change their preferences following deliberation. Thanks to their volatility, this second group can provide different majorities and so to be crucial in any electoral dynamics. * Italian National Research Council

Closed-Loop Targeted Memory Reactivation during Sleep Improves Spatial Navigation

Sounds associated with newly learned information that are replayed during non-rapid eye movement (NREM) sleep can improve recall in simple tasks. The mechanism for this improvement is presumed to be reactivation of the newly learned memory during sleep when consolidation takes place. We have developed an EEG-based closed-loop system to precisely deliver sensory stimulation at the time of down-state to up-state transitions during NREM sleep. Here, we demonstrate that applying this technology to participants performing a realistic navigation task in virtual reality results in a significant improvement in navigation efficiency after sleep that is accompanied by increases in the spectral power especially in the fast (12\u201315 Hz) sleep spindle band. Our results show promise for the application of sleep-based interventions to drive improvement in real-world tasks

Serratiopeptidase reduces the invasion of osteoblasts by Staphylococcus aureus

Finding new strategies to counteract periprosthetic infection and implant failure is a main target in orthopedics. Staphylococcus aureus, the leading etiologic agent of orthopedic implant infections, is able to enter and kill osteoblasts, to stimulate pro-inflammatory chemokine secretion, to recruit osteoclasts, and to cause inflammatory osteolysis. Moreover, by entering eukaryotic cells, staphylococci hide from the host immune defenses and shelter from the extracellular antibiotics. Thus, infection persists, inflammation thrives, and a highly destructive osteomyelitis occurs around the implant. The ability of serratiopeptidase (SPEP), a metalloprotease by Serratia marcescens, to control S. aureus invasion of osteoblastic MG-63 cells and pro-inflammatory chemokine MCP-1 secretion was evaluated. Human osteoblast cells were infected with staphylococcal strains in the presence and in the absence of SPEP. Cell proliferation and cell viability were also evaluated. The release of pro-inflammatory chemokine MCP-1 was evaluated after the exposure of the osteoblast cells to staphylococcal strains. The significance of the differences in the results of each test and the relative control values was determined with Student’s t-test. SPEP impairs their invasiveness into osteoblasts, without affecting the viability and proliferation of bone cells, and tones down their production of MCP-1. We recognize SPEP as a potential tool against S. aureus bone infection and destruction

A new anti-infective strategy to reduce the spreading of antibiotic resistance by the action on adhesion-mediated virulence factors in Staphylococcus aureus.

Staphylococcus aureus is a flexible microbial pathogen frequently isolated from community-acquired and nosocomial infections. S. aureus expresses a wide array of secreted and cell surface-associated virulence factors, including proteins that promote adhesion to damaged tissue and to the surface of host cells, and that bind proteins in blood to help evade immune responses. Furthermore, surface proteins have a fundamental role in virulence related properties of S. aureus, including biofilm formation. The present study evaluates the anti-infective capabilities of a secreted protein of Serratia marcescens (serratiopeptidase, SPEP), in impairing some staphylococcal virulence-related properties, such as attachment to inert surfaces and adhesion/invasion on eukaryotic cells. SPEP seems to exert its action by modulating specific proteins. It is not assessed if this action is due to the proteolytic activity of SPEP or to a specific mechanism which triggers an out/inside signal. Proteomic studies performed on surface proteins extracted from SPEP treated S. aureus cultures revealed that a number of proteins are affected by the treatment. Among these we found the adhesin/autolysin Atl, SdrD, Sbi, EF-Tu and EF-G. EF-Tu and EF-G are known to perform a variety of function, depending on their cytoplasmic or surface localization. All these factors can facilitate bacterial colonization, persistence and invasion of host tissues. Our results suggest that SPEP could be developed as a potential "anti-infective agent" capable to hinder the entry of S. aureus into human tissues, and also impairs the ability of this pathogen to adhere to prostheses, catheters and medical device

Uso de fotos hemiesféricas para la elaboración de modelos de altura de la regeneración en Nothofagus pumilio

Martínez Pastur, G.; Lencinas, M.V.; Soler Esteban, R. CADIC-CONICET. Casilla 92 (9410) Ushuaia, Argentina. [email protected]. Cellini, J.M.; Barrera, M. Universidad Nacional de La Plata, La Plata. Argentina. Peri, P. UNPA-INTA-CONICET, Río Gallegos, Argentina.El crecimiento en altura de la regeneración es la principal variable empleada para caracterizar la continuidad de bosques primarios y manejados. Entre los condicionantes bióticos y abióticos, la cobertura del dosel determina la cantidad de luz disponible. Se desarrollaron modelos de predicción de altura de regeneración de Nothofagus pumilio en relación con parámetros de cobertura y radiación obtenidos mediante fotos hemiesféricas, para bosques primarios y manejados. Se emplearon 3700 pares de datos (edad-altura) obtenidos durante 2002-2007 en parcelas permanentes de muestreo (n=16), caracterizadas con fotos hemiesféricas empleando un lente Sigma 8mm y analizadas usando el programa Gap Light Analyzer v.2.0. Se ajustaron modelos (Altura=a.Edadb.(c+d.X+e.X²)) por medio de técnicas de regresión no-linear que utilizaron como variables independientes a la altura y la edad de las plántulas, y como variables dependientes a la cobertura de copas (CC), el índice de área foliar efectivo (IAF), la radiación global (RG) y el porcentaje de radiación global incidente (PRG). Los modelos ajustados tuvieron un ajuste aceptable (r²=61%-63%) generando curvas polimórficas donde H aumentó hasta un máximo (20-25 cm en plántulas de 6 en CC 55%, LAI 1.0, GR 12.0 W.m² o PGR 50%) para luego decrecer en todas las edades analizadas con mayores o menores valores de dichas variables. Los bosques primarios presentaron CC=89.5%, LAI=2.6, GR=3.5 W.m² y PGR=14.3%, mientras que la corta de protección presentó CC=56.5%, LAI=0.8, GR=14.1 W.m² and PGR= 57.2%. El desarrollo de estos modelos es una herramienta útil para diseñar nuevas estrategias de manejo forestal al predecir la respuesta de la regeneración.Estudio financiado por el proyecto PAE2004 22428 (SECYT-Argentina), y gracias a la colaboración de la Consultora “Servicios Forestales” y el Aserradero Los Castores (Tierra del Fuego - Argentina)

Protease treatment affects both invasion ability and biofilm formation in Listeria monocytogenes

Listeria monocytogenes is a notably invasive bacterium associated with life-threatening food-borne disease in humans. Several surface proteins have been shown to be essential in the adhesion of L. monocytogenes, and in the subsequent invasion of phagocytes. Because the control of the invasion of host cells by Listeria could potentially hinder its spread in the infected host, we have examined the effects of a protease treatment on the ability of L. monocytogenes to form biofilms and to invade tissues. We have chosen serratiopeptidase (SPEP), an extracellular metalloprotease produced by Serratia marcescens that is already widely used as an anti-inflammatory agent, and has been shown to modulate adhesin expression and to induce antibiotic sensitivity in other bacteria. Treatment of L. monocytogenes with sublethal concentrations of SPEP reduced their ability to form biofilms and to invade host cells. Zymograms of the treated cells revealed that Ami4b autolysin, internalinB, and ActA were sharply reduced. These cell-surface proteins are known to function as ligands in the interaction between these bacteria and their host cells, and our data suggest that treatment with this natural enzyme may provide a useful tool in the prevention of the initial adhesion of L. monocytogenes to the human gu

Clinical and genetic analysis of 29 Brazilian patients with Huntington’s disease-like phenotype

Huntington’s disease (HD) is a neurodegenerative disorder characterized by chorea, behavioral disturbances and dementia, caused by a pathological expansion of the CAG trinucleotide in the HTT gene. Several patients have been recognized with the typical HD phenotype without the expected mutation. The objective of this study was to assess the occurrence of diseases such as Huntington’s disease-like 2 (HDL2), spinocerebellar ataxia (SCA) 1, SCA2, SCA3, SCA7, dentatorubral-pallidoluysian atrophy (DRPLA) and choreaacanthocytosis (ChAc) among 29 Brazilian patients with a HD-like phenotype. In the group analyzed, we found 3 patients with HDL2 and 2 patients with ChAc. The diagnosis was not reached in 79.3% of the patients. HDL2 was the main cause of the HD-like phenotype in the group analyzed, and is attributable to the African ancestry of this population. However, the etiology of the disease remains undetermined in the majority of the HD negative patients with HD-like phenotype. Key words: Huntington’s disease, Huntington’s disease-like, chorea-acanthocytosis, Huntington’s disease-like 2

Fat Mass and Obesity-Associated Gene (FTO) in Eating Disorders: Evidence for Association of the rs9939609 Obesity Risk Allele with Bulimia nervosa and Anorexia nervosa

Objective: The common single nucleotide polymorphism (SNP) rs9939609 in the fat mass and obesity-associated gene (FTO) is associated with obesity. As genetic variants associated with weight regulation might also be implicated in the etiology of eating disorders, we evaluated whether SNP rs9939609 is associated with bulimia nervosa (BN) and anorexia nervosa (AN). Methods: Association of rs9939609 with BN and AN was assessed in 689 patients with AN, 477 patients with BN, 984 healthy non-population-based controls, and 3,951 population-based controls (KORA-S4). Based on the familial and premorbid occurrence of obesity in patients with BN, we hypothesized an association of the obesity risk A-allele with BN. Results: In accordance with our hypothesis, we observed evidence for association of the rs9939609 A-allele with BN when compared to the non-population-based controls (unadjusted odds ratio (OR) = 1.142, one-sided 95% confidence interval (CI) 1.001-infinity; one-sided p = 0.049) and a trend in the population-based controls (OR = 1.124, one-sided 95% CI 0.932-infinity; one-sided p = 0.056). Interestingly, compared to both control groups, we further detected a nominal association of the rs9939609 A-allele to AN (OR = 1.181, 95% CI 1.027-1.359, two-sided p = 0.020 or OR = 1.673, 95% CI 1.101-2.541, two-sided p = 0.015,). Conclusion: Our data suggest that the obesity-predisposing FTO allele might be relevant in both AN and BN. Copyright (C) 2012 S. Karger GmbH, Freibur