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Traditional agave spirits such as mezcal or tequila are produced all over Mexico using different species of Agave. Amongst them, A. angustifolia is the most popular given its agricultural extension. A. angustifolia is a wild species extensively distributed from North to Central America, and previous studies show that it is highly related to the tequila agave A. tequilana. In different regions of Mexico, A. angustifolia is cultivated under different types and levels of management, and although traditional producers identify several landraces, for the non-trained eye there are no perceivable differences. After interviews with producers from different localities in Jalisco, Mexico, we sampled A. angustifolia plants classified as different landraces, measured several morphological traits, and characterized their genetic differentiation and diversity at the genome-wide level. We included additional samples identified as A. tequilana and A. rhodacantha to evaluate their relationship with A. angustifolia. In contrast with previous studies, our pool of ca 20K high quality unlinked SNPs provided more information and helped us to distinguish different genetic groups that are congruent with the ethnobotanical landraces. We found no evidence to genetically delimitate A. tequilana, A. rhodacantha and A. angustifolia. Our large genome level dataset allows a better understanding of the genetic identity of important A. angustifolia traditional and autochthonous landraces.

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Pre-Columbian crop movement remains poorly understood, hampering a good interpretation of the domestication and diversification of Neotropical crops. To provide new insights into pre-Columbian crop movement, we applied spatial genetics to identify and compare dispersal routes of three American crops between Mesoamerica and the Andes, two important centres of pre-Columbian crop and cultural diversity. Our analysis included georeferenced simple-sequence repeats (SSR) marker datasets of 1852 genotypes of cherimoya (Annona cherimola Mill.), a perennial fruit crop that became underutilised in the Americas after the European conquest, 770 genotypes of maize (Zea mays L.) and 476 genotypes of common bean (Phaseolus vulgaris L.). Our findings show that humans brought cherimoya from Mesoamerica to present Peru through long-distance sea-trade routes across the Pacific Ocean at least 4700 yr bp, after more ancient dispersion of maize and other crops through the Mesoamerican isthmus over land and near-coastal waters. To our knowledge, this is the first evidence of pre-Columbian crop movement between Mesoamerica and the Andes across the Pacific Ocean providing new insights into pre-Columbian crop exchange in the Americas. We propose that cherimoya represents a wider group of perennial fruit crops dispersed by humans via sea-trade routes between Mesoamerica and the Andes across the Pacific Ocean.

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BACKGROUND: The Caribbean coast of Central America remains an area of malaria transmission caused by Plasmodium falciparum despite the fact that morbidity has been reduced in recent years. Parasite populations in that region show interesting characteristics such as chloroquine susceptibility and low mortality rates. Genetic structure and diversity of P. falciparum populations in the Honduras-Nicaragua border were analysed in this study. METHODS: Seven neutral microsatellite loci were analysed in 110 P. falciparum isolates from endemic areas of Honduras (n = 77) and Nicaragua (n = 33), mostly from the border region called the Moskitia. Several analyses concerning the genetic diversity, linkage disequilibrium, population structure, molecular variance, and haplotype clustering were conducted. RESULTS: There was a low level of genetic diversity in P. falciparum populations from Honduras and Nicaragua. Expected heterozigosity (H(e)) results were similarly low for both populations. A moderate differentiation was revealed by the F(ST) index between both populations, and two putative clusters were defined through a structure analysis. The main cluster grouped most of samples from Honduras and Nicaragua, while the second cluster was smaller and included all the samples from the Siuna community in Nicaragua. This result could partially explain the stronger linkage disequilibrium (LD) in the parasite population from that country. These findings are congruent with the decreasing rates of malaria endemicity in Central America.

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INTRODUCTION: The aim of this study is to analyse the evolution of the survival of patients diagnosed with prostate cancer during the period 1995-2003. MATERIAL AND METHODS: This is a population survival study of incident cases of prostate cancer in four Spanish areas: Basque Country, Girona, Murcia and Navarra. We calculated the relative survival (RS) at 5 years and its 95% confidence intervals using a cohort analysis and adjusted for age. To assess the trend in survival between the periods (1995-1999 and 2000-2003) a Poisson regression model was used, adjusting for age, region and period, obtaining the relative risk of death. RESULTS: The number of patients diagnosed during the 1995- 1999 period was 6493 and 8331 in the period 2000-03. The RS at 5 years adjusted for age increased significantly, from 75.3% (95% CI 73.3-77.2) in the period 1995-99 to 85% (95% CI 83.4-86.4) in the period 2000-03. CONCLUSION: In Spain the survival of patients with prostate cancer has increased significantly from 1999 to 2003, probably due to the advancement in diagnosis produced by the opportunistic screening of prostate-specific antigen (PSA). Differences in the dissemination and use of the PSA level could explain the observed geographic differences in the increase of survival. It would be necessary to carry out studies to quantify the produced overdiagnosis by screening with PSA in prostate cancer.

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BACKGROUND: Several countries are discussing new legislation regarding the ban on smoking in public places, based on the growing evidence of the hazards of secondhand smoke (SHS) exposure. The objective of the present study is to quantitatively assess the relationship between smoking, SHS, and serum cotinine levels in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. METHODS: From a study on lung cancer in the EPIC cohort, questionnaire information on smoking was collected at enrolment, and cotinine was measured in serum. Three statistical models were applied by using samples available in a cross-section design: (i) cotinine levels by categories combining smoking and SHS (n = 859); (ii) the effect of hours of passive smoking exposure in nonsmokers only (n = 107); (iii) the effect of the number of cigarettes consumed per day in current smokers only (n = 832). All models were adjusted for country, sex, age, and body mass index. RESULTS: Among nonsmokers, passive smokers presented significant differences in cotinine compared with nonexposed, with a marked (but not significant) difference among former-smokers. A one hour per day increment of SHS gave rise to a significant 2.58 nmol/L (0.45 ng/mL) increase in mean serum cotinine (P < 0.001). In current smokers, a one cigarette per day increment gave rise to a significant 22.44 nmol/L (3.95 ng/mL) increase in cotinine mean (P < 0.001). CONCLUSIONS: There is clear evidence that not only tobacco smoking but also involuntary exposure increases cotinine levels. IMPACT: This study strengthens the evidence for the benefits of a smoking ban in public places.

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