Characterization of Cre recombinase activity for in vivo targeting of adipocyte precursor cells.

The increased incidence of obesity and metabolic disease underscores the importance of elucidating the biology of adipose tissue development. The recent discovery of cell surface markers for prospective identification of adipose precursor cells (APCs) in vivo will greatly facilitate these studies, yet tools for specifically targeting these cells in vivo have not been identified. Here, we survey three transgenic mouse lines, Fabp4-Cre, PdgfRα-Cre, and Prx1-Cre, precisely assessing Cre-mediated recombination in adipose stromal populations and mature tissues. Our data provide key insights into the utility of these tools to modulate gene expression in adipose tissues. In particular, Fabp4-Cre is not effective to target APCs, nor is its activity restricted to these cells. PdgfRα-Cre directs recombination in the vast majority of APCs, but also targets other populations. In contrast, adipose expression of Prx1-Cre is chiefly limited to subcutaneous inguinal APCs, which will be valuable for dissection of APC functions among adipose depots

Diversidade específica da flora pratense à escala do domínio climácico

Em 2005 uma equipa alargada de fitossociólogos portugueses reuniu mais de 1000 inventários fitossociológicos publicados até a data e propôs-se clarificar a composição fitocenótica das séries de vegetação climatófilas e edafoxerófilas portuguesas e explorar a diversidade específica de plantas características das várias etapas sucessionais à escala do domínio climácico, i.e. da área ocupada por uma dada comunidade climácica (vd. Aguiar et al., Floristical and Phytocoenotucal Diversity at the Climactical Dominion, 48th IAVS Symposium, 2005). Com esse estudo, cujos resultados quedam por publicar, foram estabelecidos critérios objectivos que permitem segregar as comunidades seriais das comunidades próprias de microgeosigmeta e ficou provado o valor heurístico dos padrões espaciais da diversidade específica concretizados à escala do domínio climácico. No que à vegetação pratense diz respeito as principais conclusões retiradas por aqueles autores foram as seguintes: Em Portugal continental ocorrem 4 tipos de prados seriais: prados anuais, prados vivazes oligotróficos, prados vivazes mesotróficos, prados vivazes de solos incoerentes e prados anuais A continentalidade tem um efeito depressivo na diversidade específica da vegetação pratense Os prados anuais mostram um pico de diversidade específica de espécies características nas áreas mediterrânicas quentes (termomediterrânicas) e oceânicas Nas séries de vegetação mediterrânicas ocorrem dois máximos de diversidade específica nos extremos (em termos de complexidade estrutural) das séries de vegetação, i.e. nos bosques imaturos e nos prados anuais Nos territórios temperados a vegetação herbáceas vivaz mesotrófica é francamente mais diversa do que qualquer outra etapa sucessional Os endemismos são mais frequentes na vegetação herbácea vivaz do que nos prados anuais Os neófitos dominam a vegetação pratense Açoriana e Madeira e dificultam a sua interpretação sindinâmica Aparentemente, a flora pratense indígena é mais diversa nos Açores do que na Madeir

Management of estuarine beaches on the Amazon coast though the application of recreational carrying capacity indices

The purpose of this paper is to determine the Recreational Carrying Capacity of three estuarine beaches (Colares, Marudá and Murubira) on the Amazon coast of Brazil, based on the combined assessment of natural conditions and visitor facilities. In the final analysis, the carrying capacity of Colares beach was estimated to be 1089 visitors per day, and that of Murubira beach, 238 visitors per day. At Marudá beach, however, the inadequate quality of the water resulted in an RCC of zero, indicating that the beach should not be visited for recreational use. The results of this study may provide a valuable diagnostic tool for the development of future state and municipal coastal management programs. We believe that the procedures adopted in this study are applicable to other estuarine beaches on the Amazon coast, as well as in other estuarine beaches elsewhere with similar natural characteristics.Peer ReviewedPostprint (author's final draft

Taux d'endemicité et tendances phytogeographiques de la végétation psammophile des plages et des dunes de sable côtier dans le sud-ouest de l'Europe (Portugal continental)

In southwest Europe (mainland Portugal), the psammophilic ecosystems of coastal beaches and sand dunes are distributed by the Eurosiberian (EUR) and Mediterranean (MED) biogeographic regions. In addition to climatic and other environmental factors, distinct plant communities are mainly influenced by the instability of the coastal sands and the proximity to the sea. Psammophilic gradients determine the plant communities that occur from the first sectors of the beach until the more interior dunes, being expressed by specific floristic associations and different rates of cover, namely by endemic taxa. The analysis of 601 phytosociological relevés, conducted between 1972 and 2010, from north (Minho) to the south (Alentejo and Algarve), allowed to study the dominant communities which occur along the ecological gradient sea-interior, with the aim of better understand general spatial geomorphologic and phytogeographic trends of distribution. As for the sea-interior gradient, no endemic flora appears in the first vegetation strip (annual communities of drift lines). Yet, some endemic species appear in the embryonic shifting dunes of the back beach, with endemic species’ coverage of 1.07% (EUR) and 1.7% (MED). In the mobile dunes (white dunes) covers by endemic flora are more significant: 6.95% (EUR) against 4.14% (MED). Semi-stable dune (gray dune), is composed by three associations (EUR, MED and another of Transition (ART) which occurs between the former two), who have the highest covers for endemics: 38,89% (EUR) 43,37% (TRA) and 55,85% (MED). Do not considering specific human induced situations of degradation and erosion, a general trend of gradual coverage growth by endemic taxa, was signed from north to south, despite median overall covers (total species) are higher in the north. The endemic taxa have been separated into endemic Portuguese (EP), Iberian (EI) and European (EU) and its representativeness endorsed. The interest in the use of phytosociology in this kind of study is discusse

Sobre as comunidades de Pterospartum tridentatum sensu lato em Portugal continental

FRANCO (1971) aquando da publicação da Nova Flora de Portugal só considerou ocorrer no território nacional Pterospartum tridentatum (L.) Willk., sob o nome de Chamaespartium tridentatum (L.) P. Gibbs, contudo TALAVERA (1999), na Flora Ibérica, considerou que esta espécie era constituída por três subespécies: Pterospartum tridentatum subsp. tridentatum, Pterospartum tridentatum subsp. cantabricum (Spach) Talavera & P. Gibbs, Pterospartum tridentatum subsp. lasianthum (Spach) Talavera & P. Gibbs, que posteriormente RIVAS-MARTÍNEZ et al. (2002) reputaram serem espécies independentes. Com esta nota pretendemos esclarecer as comunidades em que estes táxones desempenham um papel importante em Portugal continental

The meaning of mainland Portugal beaches and dunes' psammophilic plant communities: a contribution to tourism management and nature conservation

Due to their position of interface between the sea and land, the flora and vegetation of coastal beaches and dunes, occupy ecologically extreme, sensitive, unique and valuable habitats. The occurrence of a large number of endemic taxa and specific plant associations endowed with key ecological services and adapted to a stressful and harsh environmental gradient, gives them a high interest for nature conservation and an important role in sustainable territorial planning. However, such ecosystems are vulnerable to the disruption caused by several anthropogenic sources. Among other global threat factors, the inevitable sea rise caused by climate change and, at a local scale, the non-negligible implications of trampling caused by disorderly coastal touristic exploitation, growing construction pressure in the littoral, and a seasonal population boom in late spring and in summer, plus all derivate forms of pollution, are threat factors to their integrity. Therefore, a correct planning of the touristic economic activities requires the understanding of the vegetation composition and spatial distribution patterns, intrinsically determined by their biogeographic context in the Euro-Siberian or Mediterranean Regions. This comprehensive work, based on a broad phytogeographic study, brings together disperse information on plant communities of the Portuguese sandy coasts (beaches and dunes), by analysing floristic compositions, chorology and ecological characteristics, and matching them with the “Nature 2000” network habitats. Resilience and vulnerability are also studied. In a nature conservation perspective, a positive balance (and a sustainable co-existence) between the preservation of natural values and human development in the Portuguese coast, will benefit with the integration of this knowledge in coastal planning and management activitie

Bioindicators of erosive dynamics in beach and dune systems in the portuguese mainland coast

The litoral psammophilic ecosystems are organized according gradients leaning from the sea to interior areas, including a succession of phytosociological associations, correspondent to well discriminate biotopes, according their geomorphologic, soil and ecological characteristics. In the stable sandy shores (in terms of erosion balance), the different communities occupy relatively wide zonal tracks, with clear transitions. However, in situations of beach downwasting and coastline retreat, the mobile sands tend to advance inland, often compressing the zonal gradient, and distinct communities tend to overlap. Since the herbaceous hemicryptophitic flora typical from the beach and instable dunes has intrinsic colonization skills, high tolerance (or even preference) to burial, and elevated growing rates, it can quickly adapt to the instability of the topographic surface, accompanying its movement to the interior. Yet, the growing rates of the woody chamaephitic vegetation, characteristic of the more interior and relatively stable dune (gray dune) are slower, in addition to a lower capability to resist to burial. Thus, sea advance and inherent sands mobility inland, combined with the dissimilar resilience of plant associations, results in the in the overlap of the chamaephitic taxa and in the amalgamation of species from different communities. The main objective of this work was to study general trends of erosion along the Portuguese softline mainland coast, based in the analysis of the dominant associations that occur along the psammophilic gradient. It was focused in the role played by some plants has bioindicators of the velocity of erosional processes caused by wind transportation, sea dynamics and coastal retreat. Plants that can be used has reliable bioindicators are identified. Correlations between the observed alterations in the theoretical model of a coastal psammophilic gradient, and the intensity of erosion are established. The intensity of the phenomenon is analyzed and quantified along different sectors of the Portuguese coast