Homo sapiens in the Americas. Overview of the earliest human expansion in the new world

Although it is widely recognised that America was the last continent to be populated by our species, researchers' views on various aspects of this process (e.g. the period in which it occurred, the area from which the colonizing populations came, the number of dispersal waves and the routes taken by these migrations) differ significantly. In this paper, we review both classical data and more recent findings from various research fields - including geology, paleoecology, archaeology, skeletal biology, and genetics - that may shed light on the dynamics of the colonization of the American continent, according to a critical reappraisal of the various hypotheses and models that have been advanced over time to explain this process

Concrete and abstract concepts in school age children

The aim of this study is to highlight what kind of information distinguishes abstract and concrete conceptual knowledge in different aged children. A familiarity-rating task has shown that 8-year-olds judged concrete concepts as very familiar while abstract concepts were judged as much less familiar with ratings increasing substantially from age 10 to age 12, according to literature showing that abstract terms are not mastered until adolescence (Schwanenflugel, 1991). The types of relation elicited by abstract and concrete concepts during development were investigated in an association production task. At all considered age levels, concrete concepts mainly activated attributive and thematic relations as well as, to a much lesser extent, taxonomic relations and stereotypes. Abstract concepts, instead, elicited mainly thematic relations and, to a much lesser extent, examples and taxonomic relations. The patterns of relations elicited were already differentiated by age 8, becoming more specific in abstract concepts with age

Pre‐historic eating patterns in Latin America and protective effects of plant‐based diets on cardiovascular risk factors

In this review, we present the contributions to nutrition science from Latin American native peoples and scientists, appreciated from a historic point of view since pre‐historic times to the modern age. Additionally, we present epidemiological and clinical studies on the area of plant‐based diets and their relation with the prevention and treatment of cardiovascular diseases conducted in recent decades, and we discuss challenges and perspectives regarding aspects of nutrition in the region

Successful extraction of insect DNA from recent copal inclusions: limits and perspectives

Insects entombed in copal, the sub-fossilized resin precursor of amber, represent a potential source of genetic data for extinct and extant, but endangered or elusive, species. Despite several studies demonstrated that it is not possible to recover endogenous DNA from insect inclusions, the preservation of biomolecules in fossilized resins samples is still under debate. In this study, we tested the possibility of obtaining endogenous ancient DNA (aDNA) molecules from insects preserved in copal, applying experimental protocols specifically designed for aDNA recovery. We were able to extract endogenous DNA molecules from one of the two samples analyzed, and to identify the taxonomic status of the specimen. Even if the sample was found well protected from external contaminants, the recovered DNA was low concentrated and extremely degraded, compared to the sample age. We conclude that it is possible to obtain genomic data from resin-entombed organisms, although we discourage aDNA analysis because of the destructive method of extraction protocols and the non-reproducibility of the results

cardiovascular manifestations in patients infected with the human immunodeficiency virus

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Zoonoses Surveillance in Italy (2000-2009): Investigation on Animals with Neurological Symptoms

Zoonoses are defined by the World Health Organization (WHO) as \u201cThose diseases and infections naturally transmitted between vertebrae animals and man\u201d (WHO 1959) (Palmer et al., 1998). They may be caused by viruses, bacteria, including chlamidiae and rickettsiae, fungi, protozoa, helminths and arthropods (Krauss et al., 2003), and transmitted directly (through contact with skin, hair, eggs, blood or secretions) or indirectly (by insect vectors and ingestion of contaminated food). Currently, 1415 pathogens for humans have been identified and of these approximately 61% (868) are agents of zoonoses, some of which manifest with neurological signs; 132 agents are also associated with emerging zoonoses (Asjo et al., 2007; Matassa, 2007; Taylor et al. , 2001). Neurological zoonoses are widespread, especially in the developing countries where they are not even diagnosed in most cases. Emerging zoonoses of recently identified pathogens are Lyme disease, cryptosporidiosis, West Nile disease, transmissible spongiform encephalopathy, and possible variants of the avian influenza virus, which have found new favourable conditions for spreading. In contrast, re-emerging zoonoses are well-known diseases considered as eradicated in a given country but recur with an exponentially increasing incidence, such as tuberculosis, leptospirosis, rabies (Matassa, 2007)

Complete mitochondrial sequences from Mesolithic Sardinia

Little is known about the genetic prehistory of Sardinia because of the scarcity of pre-Neolithic human remains. From a genetic perspective, modern Sardinians are known as genetic outliers in Europe, showing unusually high levels of internal diversity and a close relationship to early European Neolithic farmers. However, how far this peculiar genetic structure extends and how it originated was to date impossible to test. Here we present the first and oldest complete mitochondrial sequences from Sardinia, dated back to 10,000 yBP. These two individuals, while confirming a Mesolithic occupation of the island, belong to rare mtDNA lineages, which have never been found before in Mesolithic samples and that are currently present at low frequencies not only in Sardinia, but in the whole Europe. Preliminary Approximate Bayesian Computations, restricted by biased reference samples for Mesolithic Sardinia (the two typed samples) and Neolithic Europe (limited to central and north European sequences), suggest that the first inhabitants of the island have had a small or negligible contribution to the present-day Sardinian population, which mainly derives its genetic diversity from continental migration into the island by Neolithic times