O mito da homogeneidade biológica na população paleoíndia de Lagoa Santa: implicações antropológicas

Since their first discovery in 1842-1843, by Peter Lund, the human skeletal remains from Lagoa Santa, Brazil, were destined to influence, substantially, the discussion about the settlement of the Americas, from a biological perspective. Until 1970 several authors have refered to these remains as a homogenous collection, implying that these individuals represented just one biological population or "race". Mello e Alvim (1977; see also Mello e Alvim et al., 1983-1984) was the first to use explicitly the term "homogeneity" as implying a very low intra-population diversity among these late paleoindians. For her, the extremely low diversity among the Lagoa Santa specimens could be explained only by a narrow bottle neck occuring during the occupation of the region, followed by geographic isolation from other contemporary groups. The idea of a extremely low diverse population in ancient Lagoa Santa led some brazilian archeologists to elaborate on the "isolation hypothesis", and to use it to explain local characteristics of material culture and social organization. In this paper we show that even very simple quantification techniques is able to demonstrate that the Lagoa Santa early inhabitants are among the most diverse populations in the planet, as it is normally the case with Late Pleistocene/Early Holocene hunter-gatherers.Desde sua primeira descoberta entre 1842 e 1843, pelo naturalista dinamarquês Peter W. Lund, os remanescentes ósseos humanos de Lagoa Santa, Brasil Central, estavam destinados a impactar de forma indelével os estudos sobre as origens dos primeiros americanos. Entre sua primeira descoberta e a década de 1970, a palavra homogeneidade biológica foi sempre aplicada a esses remanescentes como sinônimo de identidade biológica populacional. Mello e Alvim (1977; ver também Mello e Alvim et al., 1983-1984) associou a esse termo um novo significado: o de que tal população apresentava uma diversidade biológica extremamente reduzida, quando comparada a outras populações humanas, tendo sugerido, a partir daí, que a população antiga de Lagoa Santa teria sido formada originalmente por poucos indivíduos e vivido de forma isolada de outras populações contemporâneas. Essa sugestão teve grande impacto na comunidade arqueológica brasileira, levando alguns arqueólogos a tentar compreender certos aspectos da cultura material e da organização social desses primeiros americanos da perspectiva do isolamento. Neste trabalho demonstramos, com a ajuda de cálculos simples sobre quantificação em antropologia, disponíveis na literatura há pelo menos um século, que a proposta de Mello e Alvim (1977) não resiste nem mesmo a uma análise superficial dos dados disponíveis sobre a variabilidade craniométrica desses primeiros americanos. Contrariamente à proposta daquela autora, a população paleoíndia tardia de Lagoa Santa está entre as populações humanas mundiais mais diversas biologicamente

Estudo sobre a influência da compactação na resistência do betão à carbonatação

Trabalho apresentado em 6º Congresso Luso-Moçambicano de Engenharia, 2011 Maputo, MoçambiqueN/

Human occupation and paleoenvironments in South America: expanding the notion of an “Archaic Gap”

Uma revisão das informações arqueológicas produzidas no Brasil e países vizinhos durante as últimas décadas, aliada a uma análise de estudos paleoambientais recentes, sugerem que durante o Holoceno Médio amplas áreas da América do Sul deixaram de ser ocupadas por grupos humanos. Dados independentes, como datações de esqueletos humanos, estratigrafia de abrigos rochosos e cronologia de sítios arqueológicos a céu aberto convergem para a idéia de que tais áreas foram, no mínimo, fortemente depopuladas. Dados paleoambientais sugerem que eventos de seca constituíram a principal causa por trás das tendências observadas. Nossas conclusões expandem a noção já existente de que estresses climáticos têm um papel importante na conformação de assentamentos humanos em ambientes marginais, como desertos e altitudes elevadas, mostrando que o mesmo pode ocorrer nas terras baixas tropicais e subtropicais.An overview of the archaeological data produced in the last decades for Brazil and neighbouring countries, coupled with a background of recent studies on paleoenvironments, suggests that during the mid-Holocene vast areas of South America ceased to be occupied by human groups. Independent data coming from dated human skeletons, rockshelter stratigraphy, and chronology of open-air sites converge to the idea that these areas were, at least, strongly depopulated. Paleoenvironmental data suggest that dryness events constitute the major cause behind the observed trends. Our conclusions expand the already perceived notion that climatic stresses had a major role in the shaping of human settlement patterns in marginal environments, such as deserts and high-altitude settings, showing that the same can occur in tropical and subtropical lowlands

The occurrence of the Monarch butterfly, Danaus plexippus L. in the Azores, with a brief review of its biology.

The Monarch butterfly, Danaus plexippus L. (Lepidoptera, Nymphalidae), has been an occasional visitor to the Azores. However, during the last two decades it has become a resident species in these islands and has adapted its behaviour to the geographic conditions of this new habitat, feeding on Gomphocarpus fruticosus (L.) Aiton fil. (Asclepiadaceae). The first confirmed breeding of this butterfly in the Azores (Faial island) is reported here and dates from the summer of 1994. However, previous sightings of only a very few adult individuals indicate that there was already a small resident population before 1994. Breeding was confirmed in three additional sites: on 3 June 1999, three adults of Monarch butterfly were observed laying eggs on G. fruticosus bushes near Ribeirinha and on 28 June 1999, several caterpillars were found in the same place. Larvae were also found at S. Roque (Pico island) and larvae and pupae at S. Carlos (Terceira island) in the summer of 1999. Monarch butterflies have been observed, occasionally, in Faial, Pico, Terceira, São Miguel, Santa Maria and Corvo during winter and spring, indicating the existence of a resident population all year round, but the vegetation used for wintering shelters has not yet been confirmed

Mixtures of polymers and cholinium-based ionic liquids to tailor the phase diagrams and extraction efficiency of aqueous biphasic systems

Aqueous biphasic systems (ABS) are outstanding alternatives over conventional liquid-liquid extraction processes since it is avoided the use of volatile and hazardous organic solvents (VOCs). ABS are more biocompatible systems formed by two aqueous-rich phases that can be designed by combining different pairs of solutes (polymer-polymer, polymer-salt or salt-salt) above specific concentrations. In the past years, ABS have been studied as powerful techniques for purification, separation and extraction purposes. Ionic liquids (ILs) have been described as interesting fluids towards the development of more sustainable processes. Due to the ILs unique properties, their introduction in ABS led to systems with higher selectivity and extraction performance for a wide plethora of compounds. In fact, it was already shown that ILs allow to overcome the low hydrophilic-hydrophobic range of ABS composed of two polymers or one polymer and one inorganic salt. IL-based ABS formed with polyethylene glycol (PEG) polymers were recently introduced and a successful control of the phase polarities, through the manipulation of the IL chemical structure, was demonstrated. Lately, it was also demonstrated that a new class of natural-derived cholinium-based ILs are capable of undergoing two phase separation by the addition of PEGs with different molecular weights. In the present work, mixtures of PEGs with different molecular weights (400 and 2000 g/mol) were used to ascertain on the formation ability of ABS composed of water and cholinium-based ILs or salts. The results obtained indicate that the formation ability of these ABS increase with the content of PEG2000 over PEG400 (and follow a continuous increase), meaning that a close-fitting control on their phases polarity can be attained. These systems were then evaluated on their performance for extracting a series of alkaloids with different polarities, namely caffeine, theophylline, theobromine and nicotine. In general, the alkaloids partition extent to the most hydrophobic phase (PEG-rich) follows their polarity/hydrophobicity. In summary, it is here demonstrated that mixtures of polymers as phase-forming components of ABS allow to tailor the partition coefficients of different alkaloids and their use in the purification of added-value compounds from biomass extracts is straightforwardly foreseen.publishe

Mycobacteria-induced anaemia revisited : a molecular approach reveals the involvement of NRAMP1 and lipocalin-2, but not of hepcidin

Anaemia is a frequent complication of chronic infectious diseases but the exact mechanisms by which it develops remain to be clarified. In the present work, we used a mouse model of mycobacterial infection to study molecular alterations of iron metabolism induced by infection. We show that four weeks after infection with Mycobacterium avium BALB/c mice exhibited a moderate anaemia, which was not accompanied by an increase on hepatic hepcidin mRNA expression. Instead, infected mice presented increased mRNA expression of ferroportin (Slc40a1), ceruloplasmin (Cp), hemopexin (Hpx), heme-oxygenase-1 (Hmox1) and lipocalin-2 (Lcn2). Both the anaemia and the mRNA expression changes of iron-related genes were largely absent in C.D2 mice which bear a functional allele of the Nramp1 gene. Data presented in this work suggest that anaemia due to a chronic mycobacterial infection may develop in the absence of elevated hepcidin expression, is influenced by Nramp1 and may involve lipocalin-2.This work was supported by the EEC Framework 6 (LSHM-CT-2006037296 EuroIron1) and FCT-approved grant POCTI/MGI/40132/2001, funded by FEDER. Sandro Gomes was supported by FCT PhD grant SFRH/BD/29257/2006

A study on the immunological basis of the dissociation between type I-hypersensitivity skin reactions to Blomia tropicalis antigens and serum anti-B. tropicalis IgE antibodies

<p>Abstract</p> <p>Background</p> <p>Two conditions are used as markers of atopy: the presence of circulating anti-allergen IgE antibodies and the presence of positive skin prick test (SPT) reactions to allergenic extracts. The correlation between these conditions is not absolute. This study aimed at investigating immunological parameters that may mediate this lack of correlation. Individuals whose sera contained anti-<it>B. tropicalis </it>extract IgE antibodies (α<it>-Bt</it>E IgE) were divided into two groups, according to the presence or absence of skin reactivity to <it>B. tropicalis </it>extract (<it>Bt</it>E). The following parameters were investigated: total IgE levels; α<it>-Bt</it>E IgE levels; an arbitrary α<it>-Bt</it>E IgE/total IgE ratio; the proportion of carbohydrate-reactive α<it>-Bt</it>E IgE; the proportion of α<it>-Bt</it>E IgE that reacted with <it>Ascaris lumbricoides </it>extract (<it>Al</it>E); the production of IL-10 by <it>Bt</it>E- and <it>Al</it>E-stimulated peripheral blood cells (PBMC).</p> <p>Results</p> <p>Total IgE levels were similar in the two groups, but α<it>-Bt</it>E IgE was significantly higher in the SPT-positive group (SPT<b>+</b>). A large overlap of α<it>-Bt</it>E IgE levels was found in individuals of both groups, indicating that these levels alone cannot account for the differences in SPT outcome. Individuals of the two groups did not differ, statistically, in the proportion of α-<it>Bt</it>E IgE that reacted with carbohydrate and in the production of IL-10 by <it>Bt</it>E- and <it>Al</it>E-stimulated PBMC. Both groups had part of α-<it>Bt</it>E IgE activity absorbed out by <it>Al</it>E, indicating the existence of cross-reactive IgE antibodies. However, the α-<it>Bt</it>E IgE from the SPT-negative individuals (SPT-) was more absorbed with <it>AlE </it>than the α-<it>Bt</it>E IgE from the SPT+ individuals. This finding may be ascribed to avidity differences of the α-<it>Bt</it>E IgE that is present in the two groups of individuals, and could occur if at least part of the α-<it>Bt</it>E IgE from the SPT- individuals were elicited by <it>A. lumbricoides </it>infection.</p> <p>Conclusion</p> <p>The present results suggest that a low ratio of specific IgE to total IgE levels (in a minority of individuals), and differences in α-<it>Bt</it>E IgE avidities (which would have high affinities for <it>A. lumbricoides </it>antigens in SPT- than in SPT<b>+ </b>individuals) may play a role in the down-modulation of type-I hypersensitivity reaction against aeroallergens described in helminth-infected individuals.</p

In vitro degradation and in vivo biocompatibility of chitosan-poly(butylene succinate) fiber mesh scaffolds

In tissue engineering, the evaluation of the host response to the biomaterial implantation must be assessed to determine the extent of the inflammatory reaction. We studied the degradation of poly(butylene succinate) and chitosan in vitro using lipase and lysozyme enzymes, respectively. The subcutaneous implantation of the scaffolds was performed to assess tissue response. The type of inflammatory cells present in the surrounding tissue, as well as within the scaffold, was determined histologically and by immunohistochemistry. In the presence of lipase or lysozyme, the water uptake of the scaffolds increased. Based on the weight loss data and scanning electron microscopy analysis, the lysozyme combined with lipase had a notable effect on the in vitro degradation of the scaffolds. The in vivo implantation showed a normal inflammatory response, with presence of neutrophils, in a first stage, and macrophages, lymphocytes, and giant cells in a later stage. Vascularization in the surrounding tissue and within the implant increased with time. Moreover, the collagen deposition increased with time inside the implant. In vivo, the scaffolds maintained the structural integrity. The degradation in vitro was faster and greater compared to that observed in vivo within the same time periods.Ana R Costa-Pinto was supported by the scholarship SFRH/24735/2005 from the Portuguese “Fundação para a Ciência e a Tecnologia” (FCT). This work was partially supported by the European Network of Excellence EXPERTISSUES (NMP3-CT-2004-500283) and FCT funded project Maxbone (PTDC/ SAU-ENB/115179/2009)

Diet of mid-Atlantic Sowerby’s beaked whales Mesoplodon bidens

Copyright © 2011 Elsevier Ltd. All rights reserved.The first mid-Atlantic diet of Mesoplodon beaked whales is presented, from ten Sowerby's Mesoplodon bidens stranded in the Azores region between 2002 and 2009. This doubles the worldwide number of stomachs sampled, and reveals new feeding habits for this species. The mean number of prey items per stomach was 85±89 (range: 12–238), with fish accounting for 99.3% and cephalopods contributing less than 1% of total prey. Fish otoliths from 15 families and cephalopod lower mandibles from three families were identified, representing 22 taxa. The diet consisted mainly of small mid-water fish, the most numerous being Diaphus sp., Lampanyctus sp. and Melamphaidae species. Myctophids were present in all stranded individuals, followed by Diretmidae, Melamphaidae and Opisthoproctus soleatus, while the remaining fish species were scarce or single occurrences. Consistency of diet in four different years reveals a divergence from all previous records in continental areas, where mainly neritic and shelf-break benthopelagic fish species have been reported. Mid-Atlantic Sowerby's beaked whales' showed dietary plasticity, feeding on the most abundant mid-water groups occurring between 0 and750 m. Trophic level from prey numerical frequency was estimated at 4.4±0.46

Uncommon acquired Gerbode defect following extensive bicuspid aortic valve endocarditis

Gerbode defect is a rare type of left ventricle to right atrium shunt. It is usually congenital in origin, but acquired cases are also described, mainly following infective endocarditis, valve replacement, trauma or acute myocardial infarction. We report a case of a 50-year-old man who suffered an extensive and complex infective endocarditis involving a bicuspid aortic valve, the mitral-aortic intervalvular fibrosa and the anterior leaflet of the mitral valve. After dual valve replacement and annular reconstruction, a shunt between the left ventricle and the right atrium - Gerbode defect, and a severe leak of the mitral prosthesis were detected. Reintervention was performed with successful shunt closure with an autologous pericardial patch and paravalvular leak correction. No major complications occurred denying the immediate post-surgery period and the follow-up at the first year was uneventful