Xeroderma Pigmentosum

Xeroderma pigmentosum (XP) is defined by extreme sensitivity to sunlight, resulting in sunburn, pigment changes in the skin and a greatly elevated incidence of skin cancers. It is a rare autosomal recessive disorder and has been found in all continents and racial groups. Estimated incidences vary from 1 in 20, 000 in Japan to 1 in 250, 000 in the USA, and approximately 2.3 per million live births in Western Europe. The first features are either extreme sensitivity to sunlight, triggering severe sunburn, or, in patients who do not show this sun-sensitivity, abnormal lentiginosis (freckle-like pigmentation due to increased numbers of melanocytes) on sun-exposed areas. This is followed by areas of increased or decreased pigmentation, skin aging and multiple skin cancers, if the individuals are not protected from sunlight. A minority of patients show progressive neurological abnormalities. There are eight XP complementation groups, corresponding to eight genes, which, if defective, can result in XP. The products of these genes are involved in the repair of ultraviolet (UV)- induced damage in DNA. Seven of the gene products (XPA through G) are required to remove UV damage from the DNA. The eighth (XPV or DNA polymerase h) is required to replicate DNA containing unrepaired damage. There is wide variability in clinical features both between and within XP groups. Diagnosis is made clinically by the presence, from birth, of an acute and prolonged sunburn response at all exposed sites, unusually early lentiginosis in sun-exposed areas or onset of skin cancers at a young age. The clinical diagnosis is confirmed by cellular tests for defective DNA repair. These features distinguish XP from other photodermatoses such as solar urticaria and polymorphic light eruption, Cockayne Syndrome (no pigmentation changes, different repair defect) and other lentiginoses such as Peutz-Jeghers syndrome, Leopard syndrome and Carney complex (pigmentation not sunassociated), which are inherited in an autosomal dominant fashion. Antenatal diagnosis can be performed by measuring DNA repair or by mutation analysis in CVS cells or in amniocytes. Although there is no cure for XP, the skin effects can be minimised by rigorous protection from sunlight and early removal of pre-cancerous lesions. In the absence of neurological problems and with lifetime protection against sunlight, the prognosis is good. In patients with neurological problems, these are progressive, leading to disabilities and a shortened lifespan

Diversification and the Optimal Construction of Basis Portfolios

Nontrivial diversification possibilities arise when a factor model describes security returns. In this paper, we provide a comprehensive examination of the merits of various strategies for constructing basis portfolios that are, in principle, highly correlated with the common factors underlying security returns. Three main conclusions emerge from our study. First, increasing the number of securities included in the analysis dramatically improves basis portfolio performance. Our results indicate that factor models involving 750 securities provide markedly superior performance to those involving 30 or 250 securities. Second, comparatively efficient estimation procedures such as maximum likelihood and restricted maximum likelihood factor analysis (which imposes the APT mean restriction) significantly outperform the less efficient instrumental variables and principal components procedures that have been proposed in the literature. Third, a variant of the usual Fama-MacBeth portfolio formation procedure, which we call the minimum idiosyncratic risk portfolio formation procedure, outperformed the Fama-MacBeth procedure and proved equal to or better than more expensive quadratic programming procedures.

Mutual Fund Performance Evaluation: A Comparison of Benchmarks and Benchmark Comparisons

Our primary goal in this paper is to ascertain whether the absolute and relative rankings of managed funds are sensitive to the benchmark chosen to measure normal performance. We employ the standard CAPM benchmarks and a variety of APT benchmarks to investigate this question. We found that there is little similarity between the absolute and relative mutual fund rankings obtained from alternative benchmarks which suggests the importance of knowing the appropriate model for risk and expected return in this context. In addition, the rankings are quite sensitive to the method used to construct the APT benchmark. One would reach very different conclusions about the funds' performance using smaller numbers of securities in the analysis or the less efficient methods for estimating the necessary factor models than one would arrive at using the maximum likelihood procedures with 750 securities. We did, however, find the rankings of the funds are not very sensitive to the exact number of common sources of systematic risk that are assumed to impinge on security returns. Finally, we found statistically significant measured abnormal performance using all the benchmarks. The economic explanation of this phenomenon appears to be an open question.

The Empirical Foundations of the Arbitrage Pricing Theory I: The Empirical Tests

This paper provides a detailed and extensive examination of the validity of the APT based on maximum likelihood factor analysis of large cross-sections of securities. Our empirical implementation of the theory proved in capable of explaining expected returns on portfolios composed of securities with different market capitalizations although it provided an adequate account of the expected returns of portfolios formed on the basis of dividend yield and own variance where risk adjustment with the CAPM employing the usual market proxies failed. In addition, it appears that the zero beta version of the APT is sharply rejected in favor of the riskless rate model and that there is little basis for discriminating among five and ten factor versions of the theory.

Intercultural Universities in Mexico: Identity and Inclusion

AbstractThe purpose of this paper is to explore the ethos ofinterculturalidadin Mexico's recently foundeduniversidades interculturales. On the basis of documentation and interviews with faculty in five universities, institutionalisation of intercultural higher education within the state sector can be seen to have created a space in which the politics of recognition meet the radical ideas of educators in the tradition of constructivism andeducación popular. Intercultural higher education does not select students on the basis of race, but the location of the campuses and the content of courses are designed to attract indigenous students. The introduction of field research early in the undergraduate course should transform the relationship between students and their communities of origin, and prepare them for leadership roles. The article concludes with a critique of what it calls ‘hard’ multiculturalism.This research for this paper was funded by a British Academy large grant entitled ‘Multiculturalism in Latin America: a study in the diffusion of ideas’ which lasted from 2006 to 2011.This is the accepted version of the original publication, which appeared in the Journal of Latin American Studies and is available online at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9070750&fulltextType=RA&fileId=S0022216X13001193; http://dx.doi.org/10.1017/S0022216X13001193

Religion as heritage, religion as belief: Shifting frontiers of secularism in Europe, the USA and Brazil

This article draws a distinction between religion as heritage and as belief, and also shows the complications which arise in predominantly Christian countries when ‘new arrivals’ and evangelical, Pentecostal, or conversion-led, movements claim the recognition which has historically been afforded to hegemonic churches. Using evidence from Europe, the USA and Brazil it reveals the uncertain implementation of the state–religion boundary in the law, in taxation and in politics, and shows how even the most secular states allow religious institutions special exemptions, albeit in different ways. It asks whether religion is not producing demands amounting to a separate citizenship and why religious expression should require privileged treatment additional to freedom of speech in a secular world where religious affiliation is regarded as a matter of personal choice. It also questions the assumption of market theories of religion that more and more intense religion is good for religion and good for society. This work was supported by the Arts and Humanities Research Council [grant number AH/F007566/1].This is the accepted version of the article. The original publication of the Version of Record was in International Sociology November 2013 vol. 28 no. 6 645-662 and is available online at http://iss.sagepub.com/content/28/6/645

Brazil elections 2018: the destabilising effects of breathtaking judicial discretion

The discretionary decisions and interminable in-fighting of Brazil’s vast and intricate judicial system have significant consequences for election outcomes, and 2018 is no exception, writes David Lehmann (Federal University of Bahia). The Brazilian electoral system is regulated by the Superior Electoral Court (TSE), itself presided over by a supreme court justice and staffed by a weighty electoral bureaucracy. Some of the rules governing the electoral process, especially those concerning campaign finance, have been made by the TSE independently of particular legislation, and their effects can be seen in election outcomes, most notably increases in the turnover of deputies and the number of women and wealthy individuals elected