Browsing by Author "Duarte, Joao"
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- AFLP assessment of the genetic relationships among 12 Thymus taxa occurring in PortugalPublication . da Silva, David V.; Duarte, Joao; Miguel, Maria Graca; Leitão, JoséThymus is a widely distributed genus in the Mediterranean region with several species endemic to the Iberian Peninsula. The genetic relationships among the 12 major Thymus taxa, T. albicans, T. caespititius, T. camphoratus, T. capitellatus, T. carnosus, T.lotocephalus, T. mastichina L. ssp. mastichina, T. pulegioides, T. villosus ssp. lusitanicus, T. villosus ssp. villosus, T. zygis ssp. sylvestris and T. zygis ssp. zygis, which occur in Portugal were assessed by AFLP (Amplified Fragment Length Polymorphisms) markers. A general agreement was found between the genetic relationships estimated by the AFLP markers and the accepted Thymus taxonomy based on morphological traits and essential oil content. The AFLP markers also supported suggestions for refinement of the taxonomy of this genus.
- Family culture and adolescent sexualityPublication . Ferreira, Manuela; Nelas, Paula; Duarte, Joao; Albuquerque, Carlos; Grilo, Celia; Nave, FilipeBackground: Adolescence is characterized by an increase in autonomy and the transformation of family relationships. Their experience has different meanings in future quality of life. Objectives: To analyze the relationship between the sociodemographic variables, of Sexual context and attitudes adopted by teenagers facing sexuality with the organizational culture of the family. Methods: Observational descriptive and correlational, transversal study. The non-probabilistic convenience sample consists of 1216 adolescents attending the 9th year of study in Portuguese Public Schools and is part of the project PTDC/CPE-CED/103313/2008, the questionnaire applied was family organizational culture of Nave (2007) and attitudes towards sexuality of Nelas et al (2010). Results: The majority lives in a village (47.5% of boys and 50.0% girls).12.9%of boys do not use condoms in all relationships, and the same applies to 17.8% of girls. They belong mostly (55.8% boys and 49.5% girls) to a family with poor interpersonal relationships culture. The majority (51.8%) males and (58.9%) females have a family with moderate heuristic culture. Boys and girls (33.6% and 36.9%) both demonstrate a predominantly moderate hierarchy family culture and a moderate social goals family culture as well. Adolescents who have a bad attitude towards sexuality, mostly (43.2%) present a weak interpersonal relationships family culture with statistical significance (chi(2) = 32,092, p = 0.000) and have moderate hierarchy family culture and also moderate social goals family culture, without statistical significance. Conclusion: The family that loves, welcomes and cares is the same that educates and informs about sexuality, promoting youth empowerment making them safer, healthier and happier (C) 2013 Elsevier Espana, S.L. Open access under CC BY-NC-ND license
- The role of climate, marine influence and sedimentation rates in late-Holocene estuarine evolution (SW Portugal)Publication . Costa, Ana Maria; Freitas, Maria da Conceicao; Leira, Manel; Costas, S.; Costa, Pedro J. M.; Andrade, Cesar; Bao, Roberto; Duarte, Joao; Rodrigues, Aurora; Cachao, Mario; Araujo, Ana Cristina; Diniz, Mariana; Arias, PabloEstuaries are sensitive to changes in global to regional sea level, to climate-driven variation in rainfall and to fluvial discharge. In this study, we use source and environmentally sensitive proxies together with radiocarbon dating to examine a 7-m-thick sedimentary record from the Sado estuary accumulated throughout the last 3.6 kyr. The lithofacies, geochemistry and diatom assemblages in the sediments accumulated between 3570 and 3240 cal. BP indicate a mixture between terrestrial and marine sources. The relative contribution of each source varied through time as sedimentation progressed in a low intertidal to high subtidal and low-energy accreting tidal flat. The sedimentation proceeded under a general pattern of drier and higher aridity conditions, punctuated by century-long changes of the rainfall regime that mirror an increase in storminess that affected SW Portugal and Europe. The sediment sequence contains evidence of two periods characterized by downstream displacement of the estuarine/freshwater transitional boundary, dated to 3570-3400 cal. BP and 3300-3240 cal. BP. These are intercalated by one episode where marine influence shifted upstream. All sedimentation episodes developed under high terrestrial sediment delivery to this transitional region, leading to exceptionally high sedimentation rates, independently of the relative expression of terrestrial/marine influences in sediment facies. Our data show that these disturbances are mainly climate-driven and related to variations in rainfall and only secondarily with regional sea-level oscillations. From 3240 cal. BP onwards, an abrupt change in sediment facies is noted, in which the silting estuarine bottom reaches mean sea level and continued accreting until present under prevailing freshwater conditions, the tidal flat changing to an alluvial plain. The environmental modification is accompanied by a pronounced change in sedimentation rate that decreased by two orders of magnitude, reflecting the loss of accommodation space rather than the influence of climate or regional sea-level drivers.