Central Portugal (central + portugal)

Distribution by Scientific Domains
Earth and Environmental Science60%

Selected Abstracts

Analysis of TPI gene promoter variation in three sub-Saharan Africa population samples

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2009
Licínio Manco
Population samples from Angola, Mozambique, and S. Tomé e Príncipe were screened for the TPI gene promoter variants -5A,G, -8G,A and -24T,G. Three haplotypes were identified in the three populations: the haplotype -5A-8G-24T (average frequency 65.3%) and two less common haplotypes -5G-8G-24T (average frequency 24.7%) and -5G-8A-24T (average frequency 10.0%). A population sample from Central Portugal showed the haplotype -5A-8G-24T in 139 chromosomes and one subject heterozygous for haplotype -5G-8A-24G. The exact test of sample differentiation among three groups of malaria-infected individuals classified according to the severity of the disease showed no significant differences. We confirmed TPI gene diversity in sub-Saharan Africa, but we could not detect any association between TPI promoter variation and a malarial protective effect. Larger scale epidemiological studies are thus required to clarify this putative mechanism of natural host defense against this worldwide public health problem. Am. J. Hum. Biol., 2009. © 2008 Wiley-Liss, Inc. [source]

Stratigraphy and formation processes of the Upper Pleistocene deposit at Gruta da Oliveira, Almonda karstic system, Torres Novas, Portugal

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 3 2009
Diego E. Angelucci
Gruta da Oliveira is a cave located in the Almonda karstic system in central Portugal. Its Upper Pleistocene fill is made up of gravitational sediments with varied biogenic and anthropogenic inputs. The archaeological sequence (35,70 ka) is fairly homogeneous, reflecting a predominantly moist climatic context modulated by millennial-scale variations. Human occupation was almost continuous throughout. In the richer archaeological layers (8,14), the anthropogenic components are in primary position, and post-depositional processes are restricted, although penecontemporaneous biological activity,such as hyena scavenging,overprinted the record. In layers 15,19, the excavated area corresponds to the footslope of a talus, where accumulation proceeded mainly through runoff and where the lithics and bones derive from occupations situated ca. 5m outward. The base of the deposit is >2m from the current base of the excavation, suggesting that Oxygen Isotope Stage (OIS)-4 and OIS-5 sediments underlay the deposit already exposed. This study confirms the archaeological integrity of the Mousterian assemblages found in the different layers, and, given the dates for layer 8, supports the hypothesis that Neanderthals survived in western Iberia until at least 35,000,38,000 calendar years ago. © 2009 Wiley Periodicals, Inc. [source]

Oblique rainfall and contemporary geomorphological dynamics (Serra da Estrela, Portugal)

HYDROLOGICAL PROCESSES, Issue 4 2004
Gonçalo Vieira
Abstract Coarse sand accumulations are polygenic microforms that attain a width of several metres, a height up to 30,40 cm, a gradient of 8,12° and a slope length up to 1 m. These accumulations are frequent in the gruss-covered plateaus of the granite mountains of central and northern Portugal, but they have been described in other mountain areas (i.e. Cairngorms, Scotland). Though these microforms are frequent features, studies on them are rare. They have been attributed to complex genesis controlled primarily by aeolian processes, but also by wash and cryogenic dynamics. Results presented here add new insights into the origin of the sand accumulations and emphasize the importance of rainsplash-saltation induced by oblique rainfall as the main transportation mechanism. The study was conducted in the Serra da Estrela, a granite mountain in central Portugal (1993 m above sea level) and is supported by a detailed mapping of the orientation of the accumulations, monitoring of the surface material and analysis of meteorological data. The results are particularly significant since they indicate that the coarse sand accumulations are very active features that show a clear climatic and ecological signal. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Weather regimes and their connection to the winter rainfall in Portugal

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 1 2005
J.A. Santos
Abstract Wintertime rainfall over Portugal is strongly coupled with the large-scale atmospheric flow in the Euro-Atlantic sector. A K -means cluster analysis, on the space spanned by a subset of the empirical orthogonal functions of the daily mean sea-level pressure fields, is performed aiming to isolate the weather regimes responsible for the interannual variability of the winter precipitation. Each daily circulation pattern is keyed to a set of five weather regimes (C, W, NAO,, NAO+ and E). The dynamical structure of each regime substantiates the statistical properties of the respective rainfall distribution and validates the clustering technique. The C regime is related to low-pressure systems over the North Atlantic that induce southwesterly and westerly moist winds over the country. The W regime is characterized by westerly disturbed weather associated with low-pressure systems mainly located over northern Europe. The NAO, regime is manifested by weak low-pressure systems near Portugal. The NAO+ regime corresponds to a well-developed Azores high with generally settled and dry weather conditions. Finally, the E regime is related to anomalous strong easterly winds and rather dry conditions. Although the variability in the frequencies of occurrence of the C and NAO, regimes is largely dominant in the interannual variability of the winter rainfall throughout Portugal, the C regime is particularly meaningful over northern Portugal and the NAO, regime acquires higher relevance over southern Portugal. The inclusion of the W regime improves the description of the variability over northern and central Portugal. Dry weather conditions prevail in both the NAO+ and E regimes, with hardly any exceptions. The occurrence of the NAO+ and the NAO, regimes is also strongly coupled with the North Atlantic oscillation. Copyright © 2005 Royal Meteorological Society [source]

Destruction of microstructure in archaeological bone: a case study from Portugal

INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 6 2001
Mary Jackes
Abstract Sampling of archaeological human bone may not be justified, contrary to former high expectations regarding adult age assessment based on histomorphometry. The alterations in buried bone as a result of bacterial action are readily visible in the scanning electron microscope (SEM). An understanding of the chemical and structural changes to cortical bone requires work at the level of a few microns. This paper reports on problems encountered during analyses of samples of human bone from Mesolithic (ca. 8000 calbp) shell midden sites at Muge in central Portugal, and the methods used to try and overcome these problems. We believe we have shown that these Mesolithic bones are partly comprised of bacterially reprecipitated mineral, which has had collagen removed, with consequent obliteration of bone microstructure. We conclude that microbial destruction of the structure of archaeological bone can be a serious impediment to analysis of the characteristics of the population represented by those skeletal remains. Copyright © 2001 John Wiley & Sons, Ltd. [source]