Associations of autozygosity with a broad range of human phenotypes

In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (F-ROH) for >1.4 million individuals, we show that F-ROH is significantly associated (p <0.0005) with apparently deleterious changes in 32 out of 100 traits analysed. These changes are associated with runs of homozygosity (ROH), but not with common variant homozygosity, suggesting that genetic variants associated with inbreeding depression are predominantly rare. The effect on fertility is striking: F-ROH equivalent to the offspring of first cousins is associated with a 55% decrease [95% CI 44-66%] in the odds of having children. Finally, the effects of F-ROH are confirmed within full-sibling pairs, where the variation in F-ROH is independent of all environmental confounding.Peer reviewe

Modificação da técnica de ramaer para obtenção de plantas gêmeas de seringueira Modification of ramaer's technique to obtain twin plants of rubber tree

O objetivo deste trabalho foi aumentar a porcentagem de sucesso na obtenção de plantas gêmeas de seringueira de tamanhos iguais pela modificação da técnica de Ramaer, que utiliza sementes em fase final de germinação, quando a radícula atinge mais de 3 cm de comprimento, dificultando o seccionamento longitudinal em duas metades, a partir da inserção das alças cotiledonares. Foi testado o corte longitudinal em duas etapas, primeiro da ponta emergente da radícula, com 3 mm de comprimento, até 1 cm acima do coleto. Após a regeneração de duas radículas iguais, foi concluído o seccionamento conforme a técnica de Ramaer. A porcentagem de plantas gêmeas de tamanhos iguais foi de 82,5 com o método modificado e de 52,5 com a técnica de Ramaer.<br>The objective of this work was to enhance the success of obtaining twin rubber plants of equal size, by turning easy the Ramaer's technique, which consist of using seeds in the final stage of germination when radicle shows more than 3 cm length and the longitudinal splitting in two halves of equal size up to the cotyledonary arms. A longitudinal sectioning in two stages was tested, first of emerging tip of the radicle, 3.0 mm long, up to 1.0 cm above the root collar. After the regeneration of two equal radicles, the sectioning was concluded according to the Ramaer technique. The percentage of equal sized twin plants was 82.5 with the modified method and 52.5 with the Ramaer technique

Validity Tests of Benefit Transfer – Are We Performing the Wrong Tests?

The validity of environmental benefit transfer has been tested on numerous occasions assuming classical null hypothesis of equality. We argue against this assumption on the basis of theory, which clearly indicates that environmental benefits should be assumed to vary from context to context. We suggest the use of equivalence testing as a more appropriate and a clear compliment to the shortcomings of classical tests. Equivalence tests test the null hypothesis of difference between the original and transferred value estimates. Equivalence tests also combine the concepts of statistical significance and policy significance into one test, by defining an acceptable transfer error prior to the validity test. The results of a published study on validity of benefit transfer are reversed when subjected to an equivalence test. Copyright Springer 2005benefit transfer, contingent valuation, equivalence tests, validity,

National and International Benefit Transfer Testing with a Rigorous Test Procedure

Benefit transfer, as a mean to transfer values from existing monetary valuation studies to new policy sites, has been in use for many years. This paper aims to analyze the forecasting quality of benefit transfer by applying a rigoroust-test – also referred to as Accuracy-t-test – that takes into account testing errors which were made in previous surveys. Beside the analysis of national benefit transfers based on two German contingent valuation studies additional efforts were made to investigate into the validity and accuracy of international benefit transfer by considering two Norwegian studies that employed a similar survey design. Copyright Kluwer Academic Publishers 2004benefit transfer, contingent valuation method, water quality,

Context-Sensitive Benefit Transfer Using Stated Choice Models: Specification and Convergent Validity for Policy Analysis

benefit transfer, choice experiment, convergent validity, land management, policy decision, stated choice, land conservation,