Social security in theory and practice (II): Efficiency theories, narrative theories and implications for reform

166 countries have some kind of public old age pension. What economic forcescreate and sustain old age Social Security as a public program? Mulligan and Sala-i-Martin (1999b) document several of the internationally and historically common features of social security programs, and explore "political" theories of Social Security. This paper discusses the "efficiency theories", which view creation of the SS program as a full of partial solution to some market failure. Efficiency explanations of social security include the "SS as welfare for the elderly" the "retirement increases productivity to optimally manage human capital externalities", "optimal retirement insurance", the "prodigal father problem", the "misguided Keynesian", the "optimal longevity insurance", the "governmenteconomizing transaction costs", and the "return on human capital investment". We also analyze four "narrative" theories of social security: the "chain letter theory", the "lump of labor theory", the "monopoly capitalism theory", and the "Sub-but-Nearly-Optimal policy response to private pensions theory".The political and efficiency explanations are compared with the international and historical facts and used to derive implications for replacing the typical pay-as-you-go system with a forced savings plan. Most of the explanations suggest that forced savings does not increase welfare, and may decrease it.

Racial Stereotypes in Fictions of Slavery: Uncle Tom´s Cabin by Harriet Beecher Stowe and O Escravo by José Evaristo D’ Almeida

Most stereotypes about Africans and their descendants started with colonialism in the fifteenth century. The encounter between Africans and Europeans facilitated the creation of myths and stereotypes about the colonized peoples, which were made effective through the naturalization of differences. The relationship between skin color and slavery developed to produce a racialized system of forced labor on which colonialism depended for its survival. Stereotypes functioned to legitimize colonial authority by building the notion that the colonizer ruled over the colonized because of an innate superiority. Therefore, stereotyping is an effective "discursive strategy" (Bhabha) based on fixity and repetition with the aim of controlling the other. Harriet Beecher Stowe’s Uncle Tom’s Cabin and José Evaristo D’Almeida O Escravo both denounced the evils of slavery in the United States of America and Cape Verde respectively, claiming for the end of the institution. However, they are both ambivalent towards slaves and blacks, being unable to envisage social equality for the two races. Both authors construct their black characters as stereotypical others, but they depict the light-skin characters as superior both culturally and physically. The bi-racial characters are portrayed as the ones who possess beauty and intelligence as an inheritance from their European ancestry, while blacks are relegated to the margins. We need to consider, however, that slavery in Cape Verde had different characteristics from its counterpart in the United States of America. In Cape Verde the Africans outnumbered the Europeans and that circumstance favored miscegenation and the emergence of forms of mixed culture, which came to be seen as positive and natural. In the United States of America miscegenation was regarded as a taboo since early. And even after Emancipation, “the one-drop rule” made the offspring of an African descendant black, however 'white' he or she might be.

Skin problems associated with pegylated liposomal doxorubicin-more than palmoplantar erythrodysesthesia syndrome.

Liposomal pegylated doxorubicin is an encapsulation form of doxorubicin, with an improved pharmacokinetic profile and the ability to selectively accumulate into tumor tissue. As a result, the tolerated dose of the drug can be increased, followed by a reduced incidence of neutropenia and cardiotoxicity in comparison to doxorubucin treatment. However, a common adverse dose-schedule limiting effect of the treatment is palmoplantar erythrodysesthesia syndrome. In this retrospective study we included six patients hospitalised in the University Hospital of Zurich during the last 2 years, in connection with side effects caused by pegylated liposomal doxorubicin. These patients received this chemotherapeutic agent for treatment of various malignancies such as breast cancer, ovarian cancer, mycosis fungoides and cutaneous B-cell lymphoma. Three of six patients in this study developed classical palmoplantar erythrodysesthesia, one developed palmoplantar erythrodysesthesia associated with extensive bullous disease, one developed eruption of lymphocyte recovery syndrome and one developed intertrigo like dermatitis with stomatitis. Pegylated liposomal doxorubicin induces various skin reactions including palmoplantar erythrodysesthesia syndrome. However, the exact clinical presentation might depend on pre-existing skin diseases.

Estudo de caso: o uso da língua portuguesa por jovens provindos de outros países no domínio privado, público e educativo

A afluência de imigrantes a Portugal, nas últimas três décadas transformou radicalmente todo o tecido social português, caracterizando-se hoje pela sua heterogeneidade. Até ao início da década de 90 do século XX, os fluxos migratórios provinham essencialmente dos Países de Língua Oficial Portuguesa, com maior incidência de Cabo Verde, Brasil e Angola. É nessa década que se registam movimentos bastante significativos de imigrantes provenientes da Europa Central e Oriental, principalmente da Ucrânia, Rússia, Roménia e Moldávia, assim como da Ásia, destacando-se os naturais da China, Índia, Paquistão e das antigas repúblicas soviéticas. De acordo com a análise apresentada pelo Instituto Nacional de Estatística em Dezembro de 2006, residiam de forma legal em Portugal 329 898 cidadãos de nacionalidade estrangeira, sendo as maiores comunidades de Cabo Verde (57 349), Brasil (41 728) e Angola (28 854). A sociedade portuguesa do século XXI, distancia-se cada vez mais do conceito de monolinguismo, tal como se evidencia no Projecto Gulbenkian “Diversidade Linguística na Escola Portuguesa”, que, segundo o estudo feito, onze por cento dos alunos residentes na área da Grande Lisboa nasceram fora de Portugal e têm como línguas maternas cinquenta e oito idiomas. É urgente uma intervenção diferente no que corresponde a esta nova realidade linguística em Portugal e sobretudo no que concerne à integração do “outro”, reconhecendo e respeitando as várias línguas maternas e culturas, como também a sua preservação a fim de possibilitar o desenvolvimento íntegro e harmonioso da identidade. A heterogeneidade da actual sociedade portuguesa impõe um olhar atento para com esta nova realidade no país, sobretudo em muitas das escolas onde a par do uso da língua portuguesa outras línguas são também usadas como forma de comunicação entre os mesmos pares, situação esta perfeitamente desajustada da realidade escolar madeirense Estudo de caso: O uso da Língua Portuguesa por jovens oriundos de outros países nos domínios privado, público e educativo. 10 de inícios da década de 90 do século XX, à excepção dos alunos provenientes da Venezuela, os denominados luso-descendentes. A escola mudara, tudo se alterara, havia que tentar perceber o que estava a ocorrer, um novo Mundo “invadira” as turmas, prontas a aprender, a saber, a descobrir. Era preciso preencher o silêncio expectante. Aprender uma nova língua, a portuguesa, decorrente da obrigatoriedade implícita de tratar-se da língua oficial, obrigava a repensar o ensino, a continuamente desvendar novos caminhos possibilitadores de encontro entre a língua materna e a segunda, de reencontro com a identidade linguística e cultural que não se quer perdidas, só tornado possível na diferença. A par de uma escola que se apresentava de forma diferente, cuja intervenção teria de ser oposta à de então, uma vez que a aprendizagem do português era feita como língua segunda (L2), muitas foram e são as inquietações, um turbilhão de interrogações decorriam deste contacto constante de uma língua que se diz minha, fonte de partilha com outros jovens. O uso da língua portuguesa confinar-se-á unicamente à escola com os professores e colegas ou despoletará curiosidades, vontades, interesses, motivados por objectivos confinados ao percurso e à história humana? Muitas são as interrogações que ocorrem, muitos são também os momentos de sabedoria mútua de línguas e países a desvendar num contínuo ininterrupto e é essa constante procura que determina a busca de respostas. Entre muitas interrogações uma afigurava-se de forma latente, quiçá fonte de resposta para outras interrogações inerentes à língua portuguesa como língua segunda. A sua utilização por parte dos alunos de outras nacionalidades nos domínios privado, público e educativo engloba domínios diversos capazes de informar acerca do uso dessa mesma língua. Importa no entanto reforçar que estes alunos constituem um grupo heterogéneo sob diversos pontos de vista: etário, linguístico e cultural. Do ponto de vista linguístico a população que tem o português como língua segunda abrange alunos falantes de diferentes línguas maternas, umas mais próximas, outras mais afastadas do português, propiciando diferentes graus de transferência de conhecimentos linguísticos e de experiências comunicativas, como também em diferentes estádios de aquisição e que fora da escola o usam em maior ou menor número de contextos e com um grau de frequência desigual. Estudo de caso: O uso da Língua Portuguesa por jovens oriundos de outros países nos domínios privado, público e educativo. 11 Dispõem também de diferentes capacidades individuais para discriminar, segmentar e produzir sequências linguísticas. Já do ponto de vista cultural apresentam diferentes hábitos de aprendizagem, bem como diferentes representações e expectativas face à escola. Todos estes factores determinarão ritmos de progressão distintos no que respeita à aprendizagem do português como língua segunda. As oportunidades de aprendizagem e de uso que cada indivíduo tem ao longo da vida, determinantes no processo de aquisição, desenvolvimento e aprendizagem de uma língua, variam bastante de indivíduo para indivíduo. Os alunos podem viver num mesmo contexto no entanto razões variadíssimas determinarão diferentes oportunidades de aprendizagem e de uso. Viver-se num contexto de imersão não é suficiente para que todos tenham o mesmo grau de exposição a material linguístico rico e variado da L2. Essas oportunidades também se relacionam com a distância linguística entre língua primeira (L1) e a língua segunda, quanto mais afastadas são as duas línguas mais os falantes da L2 se refugiam na sua língua materna, assim como também se associam aos hábitos culturais da comunidade e da família.

Estudo de caso : o uso da língua portuguesa por jovens provindos de outros países no domínio privado, público e educativo

A afluência de imigrantes a Portugal, nas últimas três décadas transformou radicalmente todo o tecido social português, caracterizando-se hoje pela sua heterogeneidade. Até ao início da década de 90 do século XX, os fluxos migratórios provinham essencialmente dos Países de Língua Oficial Portuguesa, com maior incidência de Cabo Verde, Brasil e Angola. É nessa década que se registam movimentos bastante significativos de imigrantes provenientes da Europa Central e Oriental, principalmente da Ucrânia, Rússia, Roménia e Moldávia, assim como da Ásia, destacando-se os naturais da China, Índia, Paquistão e das antigas repúblicas soviéticas. De acordo com a análise apresentada pelo Instituto Nacional de Estatística em Dezembro de 2006, residiam de forma legal em Portugal 329 898 cidadãos de nacionalidade estrangeira, sendo as maiores comunidades de Cabo Verde (57 349), Brasil (41 728) e Angola (28 854). A sociedade portuguesa do século XXI, distancia-se cada vez mais do conceito de monolinguismo, tal como se evidencia no Projecto Gulbenkian “Diversidade Linguística na Escola Portuguesa”, que, segundo o estudo feito, onze por cento dos alunos residentes na área da Grande Lisboa nasceram fora de Portugal e têm como línguas maternas cinquenta e oito idiomas. É urgente uma intervenção diferente no que corresponde a esta nova realidade linguística em Portugal e sobretudo no que concerne à integração do “outro”, reconhecendo e respeitando as várias línguas maternas e culturas, como também a sua preservação a fim de possibilitar o desenvolvimento íntegro e harmonioso da identidade. A heterogeneidade da actual sociedade portuguesa impõe um olhar atento para com esta nova realidade no país, sobretudo em muitas das escolas onde a par do uso da língua portuguesa outras línguas são também usadas como forma de comunicação entre os mesmos pares, situação esta perfeitamente desajustada da realidade escolar madeirense Estudo de caso: O uso da Língua Portuguesa por jovens oriundos de outros países nos domínios privado, público e educativo. 10 de inícios da década de 90 do século XX, à excepção dos alunos provenientes da Venezuela, os denominados luso-descendentes. A escola mudara, tudo se alterara, havia que tentar perceber o que estava a ocorrer, um novo Mundo “invadira” as turmas, prontas a aprender, a saber, a descobrir. Era preciso preencher o silêncio expectante. Aprender uma nova língua, a portuguesa, decorrente da obrigatoriedade implícita de tratar-se da língua oficial, obrigava a repensar o ensino, a continuamente desvendar novos caminhos possibilitadores de encontro entre a língua materna e a segunda, de reencontro com a identidade linguística e cultural que não se quer perdidas, só tornado possível na diferença. A par de uma escola que se apresentava de forma diferente, cuja intervenção teria de ser oposta à de então, uma vez que a aprendizagem do português era feita como língua segunda (L2), muitas foram e são as inquietações, um turbilhão de interrogações decorriam deste contacto constante de uma língua que se diz minha, fonte de partilha com outros jovens. O uso da língua portuguesa confinar-se-á unicamente à escola com os professores e colegas ou despoletará curiosidades, vontades, interesses, motivados por objectivos confinados ao percurso e à história humana? Muitas são as interrogações que ocorrem, muitos são também os momentos de sabedoria mútua de línguas e países a desvendar num contínuo ininterrupto e é essa constante procura que determina a busca de respostas. Entre muitas interrogações uma afigurava-se de forma latente, quiçá fonte de resposta para outras interrogações inerentes à língua portuguesa como língua segunda. A sua utilização por parte dos alunos de outras nacionalidades nos domínios privado, público e educativo engloba domínios diversos capazes de informar acerca do uso dessa mesma língua. Importa no entanto reforçar que estes alunos constituem um grupo heterogéneo sob diversos pontos de vista: etário, linguístico e cultural. Do ponto de vista linguístico a população que tem o português como língua segunda abrange alunos falantes de diferentes línguas maternas, umas mais próximas, outras mais afastadas do português, propiciando diferentes graus de transferência de conhecimentos linguísticos e de experiências comunicativas, como também em diferentes estádios de aquisição e que fora da escola o usam em maior ou menor número de contextos e com um grau de frequência desigual. Estudo de caso: O uso da Língua Portuguesa por jovens oriundos de outros países nos domínios privado, público e educativo. 11 Dispõem também de diferentes capacidades individuais para discriminar, segmentar e produzir sequências linguísticas. Já do ponto de vista cultural apresentam diferentes hábitos de aprendizagem, bem como diferentes representações e expectativas face à escola. Todos estes factores determinarão ritmos de progressão distintos no que respeita à aprendizagem do português como língua segunda. As oportunidades de aprendizagem e de uso que cada indivíduo tem ao longo da vida, determinantes no processo de aquisição, desenvolvimento e aprendizagem de uma língua, variam bastante de indivíduo para indivíduo. Os alunos podem viver num mesmo contexto no entanto razões variadíssimas determinarão diferentes oportunidades de aprendizagem e de uso. Viver-se num contexto de imersão não é suficiente para que todos tenham o mesmo grau de exposição a material linguístico rico e variado da L2. Essas oportunidades também se relacionam com a distância linguística entre língua primeira (L1) e a língua segunda, quanto mais afastadas são as duas línguas mais os falantes da L2 se refugiam na sua língua materna, assim como também se associam aos hábitos culturais da comunidade e da família.

Structural joint inversion of time-lapse crosshole ERT and GPR traveltime data

Time-lapse geophysical monitoring and inversion are valuable tools in hydrogeology for monitoring changes in the subsurface due to natural and forced (tracer) dynamics. However, the resulting models may suffer from insufficient resolution, which leads to underestimated variability and poor mass recovery. Structural joint inversion using cross-gradient constraints can provide higher-resolution models compared with individual inversions and we present the first application to time-lapse data. The results from a synthetic and field vadose zone water tracer injection experiment show that joint 3-D time-lapse inversion of crosshole electrical resistance tomography (ERT) and ground penetrating radar (GPR) traveltime data significantly improve the imaged characteristics of the point injected plume, such as lateral spreading and center of mass, as well as the overall consistency between models. The joint inversion method appears to work well for cases when one hydrological state variable (in this case moisture content) controls the time-lapse response of both geophysical methods. Citation: Doetsch, J., N. Linde, and A. Binley (2010), Structural joint inversion of time-lapse crosshole ERT and GPR traveltime data, Geophys. Res. Lett., 37, L24404, doi: 10.1029/2010GL045482.

Factor structure of the SOCRATES questionnaire in hospitalized medical patients.

The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES), a 19-item instrument developed to assess readiness to change alcohol use among individuals presenting for specialized alcohol treatment, has been used in various populations and settings. Its factor structure and concurrent validity has been described for specialized alcohol treatment settings and primary care. The purpose of this study was to determine the factor structure and concurrent validity of the SOCRATES among medical inpatients with unhealthy alcohol use not seeking help for specialized alcohol treatment. The subjects were 337 medical inpatients with unhealthy alcohol use, identified during their hospital stay. Most of them had alcohol dependence (76%). We performed an Alpha Factor Analysis (AFA) and Principal Component Analysis (PCA) of the 19 SOCRATES items, and forced 3 factors and 2 components, in order to replicate findings from Miller and Tonigan (Miller, W. R., & Tonigan, J. S., (1996). Assessing drinkers' motivations for change: The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES). Psychology of Addictive Behavior, 10, 81-89.) and Maisto et al. (Maisto, S. A., Conigliaro, J., McNeil, M., Kraemer, K., O'Connor, M., & Kelley, M. E., (1999). Factor structure of the SOCRATES in a sample of primary care patients. Addictive Behavior, 24(6), 879-892.). Our analysis supported the view that the 2 component solution proposed by Maisto et al. (Maisto, S.A., Conigliaro, J., McNeil, M., Kraemer, K., O'Connor, M., & Kelley, M.E., (1999). Factor structure of the SOCRATES in a sample of primary care patients. Addictive Behavior, 24(6), 879-892.) is more appropriate for our data than the 3 factor solution proposed by Miller and Tonigan (Miller, W. R., & Tonigan, J. S., (1996). Assessing drinkers' motivations for change: The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES). Psychology of Addictive Behavior, 10, 81-89.). The first component measured Perception of Problems and was more strongly correlated with severity of alcohol-related consequences, presence of alcohol dependence, and alcohol consumption levels (average number of drinks per day and total number of binge drinking days over the past 30 days) compared to the second component measuring Taking Action. Our findings support the view that the SOCRATES is comprised of two important readiness constructs in general medical patients identified by screening.

Fighting against Malaria: Prevent wars while waiting for the "miraculous" vaccine

The World Health Organization estimates that 300 million clinical cases of malaria occur annually and observed that during the 80's and part of the 90's its incidence increased. In this paper we explore the influence of refugees from civil wars on the incidence of malaria in the refugee-receiving countries. Using civil wars as an instrumental variable we show that for each 1,000 refugees there are between 2,000 and 2,700 cases of malaria in the refugee receiving country. On average 13% of the cases of malaria reported by the WHO are caused by forced migration as a consequence of civil wars.

Abnormal Lung Function and Risk for Heart Failure in the Elderly: The Health, Aging, and Body Composition Study

Background: Chronic obstructive pulmonary disease (COPD) has been associated with increased risk for heart failure (HF). The impact of subclinical abnormal spirometric findings on HF risk among older adults without history of COPD is not well elucidated. Methods: We evaluated 2125 participants (age 73.6±2.9 years; 50.5% men; 62.3% white; 45.6/9.4% past/current smokers; body mass index [BMI] 27.2±4.6 kg/m2) without prevalent COPD or HF who underwent baseline spirometry in the Health ABC Study. Abnormal lung function was defined either as forced vital capacity (FVC) below lower limit of normal (LLN) or forced expiratory volume in 1st sec (FEV1) to FVC ratio below LLN. Results: On follow-up (median, 9.4 years), 68 of 350 (19.4%) participants with abnormal lung function developed HF, as compared to 172 of 1775 (9.7%) participants with normal lung function (hazard ratio [HR], 2.31; 95% confidence interval [CI], 1.74 -3.06; P<.001). This increased risk persisted after adjusting for all other independent predictors of HF in the Health ABC Study, BMI, incident coronary events, and several inflammatory markers (HR, 1.82; 95% CI, 1.30 -2.54; P<.001), and remained constant over time. Baseline FVC and FEV1 had a linear association with HF risk (Figure). In adjusted models, HF risk increased by 21% (95% CI, 10 -36%) per 10% decrease in FVC and 18% (95% CI, 10 -28%) per 10% decrease in FEV1 (both P<.001); this association persisted among participants with normal lung function at baseline. Findings were consistent across sex, race, and smoking status. Conclusions: Subclinical abnormal spirometric findings are prevalent among older adults and are independently associated with risk for incident HF.

Social security in theory and practice (I): Facts and political theories

166 countries have some kind of public old age pension. What economic forcescreate and sustain old age Social Security as a public program? We document some of the internationally and historically common features of Social Security programs including explicit and implicit taxes on labor supply, pay-as-you-go features, intergenerational redistribution, benefits which areincreasing functions of lifetime earnings and not means-tested. We partition theories of Social Security into three groups: "political", "efficiency" and "narrative" theories. We explore three political theories in this paper: the majority rational voting model (with its two versions: "the elderly as the leaders of a winning coalition with the poor" and the "once and for all election" model), the "time-intensive model of political competition" and the "taxpayer protection model". Each of the explanations is compared with the international and historical facts. A companion paper explores the "efficiency" and "narrative" theories, and derives implicationsof all the theories for replacing the typical pay-as-you-go system with a forced savings plan.

In situ introducer sheath dilatation for complex aortic access.

Aortic access problems due to diseased or small peripheral vessels are a major issue in endovascular aneurysm repair (EVAR). In the emergency setting, like aortic rupture after blunt trauma, or in patients with a hostile abdomen, a more proximal access to the aorta is not a pleasant perspective. We developed in situ introducer sheath dilatation as a bail-out technique for patients with difficult aortic access under various circumstances including EVAR, intra-aortic balloon pump insertion and cannulation for perfusion. The method described allows to increase the access vessel diameter by 50% (from 6 to 9 mm) or the luminal circumference from 18 to 27 F. We have used this technique in five patients without complication, very much in contrast to the traditionally practiced 'forced device insertion'.

ARE PPARS NOVEL THERAPEUTIC TARGETS TO IMPROVE MELANOMA TREATMENT ?

Cutaneous melanoma is an aggressive malignant tumor of melanocytes, the pigment- producing cells of the epidermis, with a high incidence in developed countries. Despite some major clinical breakthroughs in the last few years, efficient therapies for metastatic melanoma, which portends a very bad prognosis, are still lacking. Among the potential therapeutic targets that have been attracting at-tention in melanoma are the peroxisome proliferator-activated receptors (PPARs). These members - a, ß and 7 - of the nuclear hormone receptor family, which are ligand-gated transcription factors endowed with a multitude of functions besides metabolism homeostasis, have displayed promising antitumor properties in a wide range of cancer cells, including melanoma. However, our knowledge of PPARs' functions in this skin cancer is far from complete, making the usefulness of any of the a, ß or 7 isotype as a therapeutic target uncertain. In this work, we showed that all three PPAR isotypes are expressed in normal melanocytes, in most melanoma cell lines and in primary and metastatic melanomas, and that PPAR/3 and 7 display transcriptional activity in normal melanocytes and melanoma cells. We also showed that the PPAR7 agonist rosiglitazone had anti-melanoma properties largely independent of PPAR7 expression, which was widely varying across the different cell lines and melanoma biopsies we evaluated and was not correlated with cell line stage. Consistent with the general view of PPAR7 as a tumor suppressor gene, we found that, in human samples, PPAR7 was less expressed in melanoma than in normal skin. Transcriptornic profiling of metastatic melanoma cells in which PPAR7 was pharmacologically modulated revealed an association with epithelial-to-mesenchymal transition, though the functional relevance of this finding remains to be determined. Collectively, our results suggests that PPAR7 activity in melanoma is highly complex and that a straightforward picture of PPAR7's role in this skin cancer is difficult to draw. In this study, we also provided compelling evidence that thioredoxin interacting protein (TXNIP) is, in melanoma, a bona fide PPAR7 target gene, the expression of which is repressed by PPAR7 activation. Although TXNIP is mostly known as an inhibitor of the major antioxidant thioredoxin, it has demonstrated a range of biological functions and is generally considered as a tumor suppressor gene. Consistently, we found that TXNIP expression is associated with growth arrest of melanoma cells in vitro and that forced expression of TXNIP strongly impairs cell proliferation. Interestingly, we also discovered that TXNIP favors melanoma cell migration while it diminishes their adhesion. Finally, we provided several lines of evidence that TXNIP may regulate these processes at the transcriptional level as well as by direct protein-protein interactions in the plasma membrane. Altogether, our findings suggest that the PPAR7 target TXNIP may be a double-edged sword in melanoma, hindering tumor growth but promoting invasion and dissemination. Experiments to evaluate the net biological outcome of TXNIP modulation in vivo are ongoing. -- Le mélanome cutané est une tumeur maligne agressive des mélanocytes, cellules de l'épiderme qui produisent la mélanine. Ce cancer présente un taux d'incidence élevé dans les pays développés et est grevé d'un pronostic très sombre une fois qu'il a disséminé. Malgré les importants progrès réalisés ces dernières années, aucune thérapie lie s'est encore montrée véritablement efficace contre le mélanome métastatique. Parmi les cibles thérapeutiques potentielles, nombre de groupes de recherche se sont penchés sur les peroxisome proliferator-activated receptors (PPARs). Ces récepteurs - a, ß et 7 - font partie de la famille des récepteurs nucléaires aux hormones, des facteurs de transcription activés par des ligands et dotés d'une multitude de fonctions en sus de la régulation du métabolisme. Ces protéines ont démontré des propriétés anti-tumorales prometteuses dans une large gamme de cellules cancéreuses, y compris le mélanome. Cependant, nous connaissons encore très mal les fonctions des PPARs dans ce cancer de la peau, rendant l'utilité thérapeutique de l'un des isotypes a, ß ou 7 incertaine. Dans ce travail, nous avons montré que les trois isotypes sont exprimés dans les mélanocytes normaux, dans la plupart des lignées de mélanome ainsi que dans des mélanomes primaires et métastatiques; nous avons aussi montré que PPAR/3 et 7 sont actifs sur le plan transcriptionnel dans les mélanocytes normaux et les cellules de mélanome. La rosiglitazone, un agoniste de PPAR7, a démontré des propriétés anti-mélanome essentiellement indépendantes de l'expression de PPAR7, qui semble très variable dans les lignées et les biopsies que nous avons évaluées; de plus, l'expression de PPAR7 n'est pas corrélée avec le stade de la lignée. En accord avec la vision communément admise de PPAR7 comme étant un gène suppresseur de tumeur, nous avons observé dans des échantillons humains que PPAR7 est moins exprimé dans les mélanomes que dans la peau normale. Une étude transcrip- tomique de cellules de mélanome métastatique a révélé que la modulation phar-macologique de PPAR7 est associée avec la transition épithélio-mésenchymateuse, même si la pertinence fonctionnelle de cette trouvaille reste à déterminer. Collec-tivement, ces résultats suggèrent que l'activité de PPAR/y dans le mélanome est hautement complexe et qu'une image claire du rôle de PPAR7 dans ce cancer est difficile à dessiner. Dans cette étude, nous avons également fourni de solides preuves que la thiore-doxin interacting protein (TXNIP) est, dans le mélanome, un gène cible bona fide de PPAR7 dont l'expression est réprimée par l'activation de PPAR7. Bien que TXNIP soit surtout connu comme un inhibiteur de la thiorédoxine -un anti-oxydant majeur - cette protéine a démontré une large gamme de fonctions biologiques et est généralement considérée comme un gène suppresseur de tumeur. En accord avec cette conception, nous avons trouvé que l'expression de TXNIP est associée avec l'arrêt de croissance des cellules de mélanome in vitro et que l'expression forcée de TXNIP freine considérablement la prolifération cellulaire. Nous avons aussi découvert que TXNIP favorise la migration des cellules de mélanome alors qu'elle diminue leur adhésion. Enfin, nous avons obtenu plusieurs preuves que TXNIP pourrait réguler ces processus tant au niveau transcriptionnel que par des interactions protéine-protéine au sein de la membrane plasmique. En conclusion, nos résultats suggèrent que la cible de PPAR7 TXNIP pourrait être une épée à double tranchant dans le mélanome, freinant la croissance tumorale mais favorisant l'invasion et la dissémination. Des expériences permettant d'évaluer l'effet biologique net de la modulation de TXNIP in vivo sont en cours.

Gerontocracy, retirement, and social security

Why are the old politically successful? We build a simple interest group model in which political pressure is time-intensive, showing that in the political competitive equilibrium each group lobbies for government policies that lower their own value of time but the old do so to a greater extent and as a result are net gainers from the political process. What distinguishes the elderly from other political groups (and what makes them more succesful) is that they have lower labor productivity and/or that we are all likely to become elderly at some point, while we are relatively unlikely to change gender, race, sexual orientation, or even ocupation, The model has a variety of implications for the design of social security programs, which we test using data from the Social Security Administration. For example, the model predicts that social security programs with retirement incentives are larger and that the old are more "single-minded" in their politics, implications which we verify using cross-country government finance data and cross-country political participation surveys. Finally, we show that the forced savings programs intended to "reform" the social security system may increase the amount of intergenerational redistribution. As a model for evaluating policy reforms, ours has the attractive feature that reforms must be time time consistent from a political point of view rather than a public interest point of view.

El campo volcánico catalán

Catalan volcanic field, in Iberian Peninsula Northeast, has been made during Neogene and Quaternary. It is made up Empordà, la Selva and la Garrotxa Zones, the best volcanic morphology is in the last one because is the most recent. In this paper we explain the volcanic rocks general characteristics, what eruption activity generate it and the final volcanic edifice morphology. Finally, we propose some crops to visit

Small airways function declines after allogeneic haematopoietic stem cell transplantation.

Bronchiolitis obliterans (BO) following allogeneic haematopoietic stem cell transplantation (HSCT) affects peripheral airways. Detection of BO is presently delayed by the low sensitivity of spirometry. We examined the relationship between peripheral airway function and time since HSCT, and compared it with spirometry and clinical indices in 33 clinically stable allogeneic HSCT recipients. The following measurements were performed: lung function, exhaled nitric oxide, forced oscillatory respiratory system resistance and reactance, acinar (S(acin)) and conductive airways ventilation heterogeneity and lung clearance index (LCI) measured by multiple breath nitrogen washout. 22 patients underwent repeat visits from which short-term changes were examined. Median time post HSCT was 12 months. Eight patients were clinically diagnosed as having BO. In multivariate analysis, time since HSCT was predicted by S(acin) and forced expiratory volume in 1 s % predicted. 20 patients had abnormal S(acin) with normal spirometry, whereas none had airflow obstruction with normal S(acin). S(acin) and LCI were the only measures to change significantly between two visits, with both worsening. Change in S(acin) was the only parameter to correlate with change in chronic graft-versus-host disease grade. In conclusion, peripheral airways ventilation heterogeneity worsens with time after HSCT. S(acin) may be more sensitive than spirometry in detecting BO at an early stage, which needs confirmation in a prospective study.