Cross-Cultural Differences in Emotional Selection on Transmission of Information

Research on cultural transmission among Americans has established a bias for transmitting stories that have disgusting elements (such as exposure to rats and maggots). Conceived of as a cultural evolutionary force, this phenomenon is one type of emotional selection. In a series of online studies with Americans and Indians we investigate whether there are cultural differences in emotional selection, such that the transmission process favours different kinds of content in different countries. The first study found a bias for disgusting content (rats and maggots) among Americans but not among Indians. Four subsequent studies focused on how country interacts with kind of emotional content (disgusting vs. happy surprises and good news) in reactions to transmission of stories or information. Whereas Indian participants, compared to Americans, tended to be less interested in, and excited by, transmission of stories and news involving common disgust-elicitors (like rats), the opposite pattern held for transmission of happy surprises and good news (e.g., the opening of a new public facility). We discuss various possible explanations and implications

TRAIL treatment provokes mutations in surviving cells

Chemotherapy and radiotherapy commonly damage DNA and trigger p53-dependent apoptosis through intrinsic apoptotic pathways. Two unfortunate consequences of this mechanism are resistance due to blockade of p53 or intrinsic apoptosis pathways, and mutagenesis of non-malignant surviving cells which can impair cellular function or provoke second malignancies. Death ligand-based drugs, such as tumor necrosis factor-related apoptosis inducing ligand (TRAIL), stimulate extrinsic apoptotic signaling, and may overcome resistance to treatments that induce intrinsic apoptosis. As death receptor ligation does not damage DNA as a primary mechanism of pro-apoptotic action, we hypothesized that surviving cells would remain genetically unscathed, suggesting that death ligand-based therapies may avoid some of the adverse effects associated with traditional cancer treatments. Surprisingly, however, treatment with sub-lethal concentrations of TRAIL or FasL was mutagenic. Mutations arose in viable cells that contained active caspases, and overexpression of the caspase-8 inhibitor crmA or silencing of caspase-8 abolished TRAIL-mediated mutagenesis. Downregulation of the apoptotic nuclease caspase-activated DNAse (CAD)/DNA fragmentation factor 40 (DFF40) prevented the DNA damage associated with TRAIL treatment. Although death ligands do not need to damage DNA in order to induce apoptosis, surviving cells nevertheless incur DNA damage after treatment with these agents

The genetics of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease caused by the interaction of genetic susceptibility and environmental influences. There is increasing evidence that genes link to disease pathogenesis and heterogeneity by causing variation in protease anti-protease systems, defence against oxidative stress and inflammation. The main methods of genomic research for complex disease traits are described, together with the genes implicated in COPD thus far, their roles in disease causation and the future for this area of investigation

Mouse models to unravel the role of inhaled pollutants on allergic sensitization and airway inflammation

Air pollutant exposure has been linked to a rise in wheezing illnesses. Clinical data highlight that exposure to mainstream tobacco smoke (MS) and environmental tobacco smoke (ETS) as well as exposure to diesel exhaust particles (DEP) could promote allergic sensitization or aggravate symptoms of asthma, suggesting a role for these inhaled pollutants in the pathogenesis of asthma. Mouse models are a valuable tool to study the potential effects of these pollutants in the pathogenesis of asthma, with the opportunity to investigate their impact during processes leading to sensitization, acute inflammation and chronic disease. Mice allow us to perform mechanistic studies and to evaluate the importance of specific cell types in asthma pathogenesis. In this review, the major clinical effects of tobacco smoke and diesel exhaust exposure regarding to asthma development and progression are described. Clinical data are compared with findings from murine models of asthma and inhalable pollutant exposure. Moreover, the potential mechanisms by which both pollutants could aggravate asthma are discussed

Evidence for weak or linear conformity but not for hyper-conformity in an everyday social learning context

Conformity is thought to be an important force in cultural evolution because it has the potential to stabilize cooperation in large groups, potentiate group selection and thus explain uniquely human behaviors. However, the effects of such conformity on cultural and biological evolution will depend much on the way individuals are influenced by the frequency of alternative behavioral options witnessed. Theoretical modeling has suggested that only what we refer to as ‘hyper-conformity’, an exaggerated tendency to perform the most frequent behavior witnessed in other individuals, is able to increase within-group homogeneity and between-group diversity, for instance. Empirically however, few experiments have addressed how the frequency of behavior witnessed affects behavior. Accordingly we performed an experiment to test for the presence of conformity in a natural situation with humans. Visitors to a Zoo exhibit were invited to write or draw answers to questions on A5 cards and potentially win a small prize. We manipulated the proportion of existing writings versus drawings visible to visitors and measured the proportion of written cards submitted. We found a strong and significant effect of the proportion of text displayed on the proportion of text in the answers, thus demonstrating social learning. We show that this effect is approximately linear, with potentially a small, weak-conformist component but no hyper-conformist one. The present experiment therefore provides evidence for linear conformity in humans in a very natural context.Publisher PDFPeer reviewe

Fibrose pulmonar idiopática: características clínicas e sobrevida em 132 pacientes com comprovação histológica Pulmonary idiopathic fibrosis: clinical findings and survival in 132 histologically-proven patients

Com o objetivo de avaliar as características clínicas e sobrevida de pacientes portadores de fibrose pulmonar idiopática, foram analisados 132 casos com confirmação histológica, internados no Pavilhão Pereira Filho entre 1970 e 1996. O diagnóstico foi realizado em 120 casos por biópsia a céu aberto e em 12 casos por biópsia transbrônquica. A idade média do grupo estudado foi de 56 anos; 78 eram do sexo masculino; 126 eram brancos e 6, negros. O tabagismo estava presente em 61 casos. A duração média dos sintomas antes do diagnóstico foi de 22,7 meses. O hipocratismo digital esteve presente em 75 pacientes e estertores teleinspiratórios foram verificados em 100 casos. Dispnéia só não foi constatada em dois pacientes e tosse esteve presente em 89 casos. As provas de função pulmonar apresentaram os seguintes valores médios: CVF, 62%; VEF1, 70%; DCO, 43,4%; CPT, 76,7%; PaO2, 67,3mmHg; PaCO2, 39,1mmHg e SaO2, 92,3%. O lavado broncoalveolar apresentou os seguintes valores médios: macrófagos, 83,8%; neutrófilos, 9,1%; linfócitos; 6,1% e eosinófilos, 0,6%. Na radiologia convencional de tórax, foi observado faveolamento em 79 casos, redução da capacidade pulmonar total em 107 e alargamento da traquéia intratorácica em 50. Na TC de tórax, o grau médio de profusão do padrão reticular foi de 42,3% e do padrão de granularidade, de 43,6%. O padrão histológico usual esteve presente em 128 casos, sendo apenas quatro pacientes portadores de padrão descamativo. Em 121 casos foram obtidas informações quanto à sobrevida em dezembro de 1997. A sobrevida média total desta série foi de 28 meses, sendo de 24 meses para os pacientes que foram a óbito. Os pacientes desta série apresentaram características associadas a um estágio avançado da doença. Este fato, mais a presença maciça de pacientes com padrão usual e a rígida seleção de casos muito provavelmente contribuíram para os resultados encontrados quanto à sobrevida.<br>In order to evaluate the clinical findings and survival of pulmonary idiopathic fibrosis patients, 132 cases with histologically-proven biopsy were studied, coming from Pavilhão Pereira Filho Hospital, from 1970 to 1996. The diagnosis was made in 120 patients by open lung biopsy and in 12 cases by transbronchial lung biopsy. The average age was 56 years; 78 were male and only 6 were black. Smoking was observed in 61 cases. Mean duration of symptoms before diagnosis was 22.7 months. Digital clubbing was present in 75 patients and teleinspiratory crackles in 100. Dyspnea was observed in all but two patients and cough was present in 89 cases. Lung function test values were: FVC, 62%; FEV1, 70%; DLCO, 43.4%; TLC, 76.7%; PaO2, 67.3 mmHg; PaCO2, 39.1 mmHg and SaO2, 92.3%. Bronchoalveolar cellularity values were: macrophages, 83.8%; neutrophils, 9.1%; lymphocytes, 6.1% and eosinophils, 0.6%. In X-ray, honeycombing was present in 79 cases, reduced total lung capacity in 107 and intrathoracic tracheal widening in 50. In CT, the mean reticular pattern profusion was 42.3% and the mean granular pattern profusion was 43.6%. The usual histologic pattern was found in 128 cases, and the descamative pattern in only 4. Information about survival was found in 121 cases until December 1997. The mean survival rate of all patients was 28 months and for dead patients was 24 months. Patient characteristics in this study were associated with advanced stage of disease, which was confirmed by small survival rates of those cases. The strong predominance of usual pattern and better patient selection may have contributed to these results