155 research outputs found

    Identité biologique des artisans moustériens de Kebara (Mont Carmel, Israël) Réflexions sur le concept de néanderthalien au Levant méditerranéen

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    DĂšs les premiĂšres dĂ©couvertes de fossiles humains provenant du Bassin MĂ©diterranĂ©en oriental et datĂ©s du PlĂ©istocĂšne supĂ©rieur, il est apparu Ă©vident que la documentation anthropologique illustrait une hĂ©tĂ©rogĂ©nĂ©itĂ© biologique, suscitant des interprĂ©tations diffĂ©rentes. Par la suite, l’enrichissement de la documentation avec de nouvelles fouilles est venu alimenter, au sein de la communautĂ© scientifique, les discussions portant aussi bien sur les affinitĂ©s phylogĂ©nĂ©tiques des fossiles que sur leur position chronologique. La prise en compte, sur ces fossiles proche-orientaux, de l’originalitĂ© de l’assemblage de caractĂšres anatomiques prĂ©sents ne doit pas ĂȘtre sous-estimĂ©e pour une meilleure Ă©valuation des composantes rĂ©gionales. C’est ce qui est proposĂ© Ă  propos de Kebara, l’objectif Ă©tant de favoriser une approche cohĂ©rente de la diversitĂ© biologique des hommes du PalĂ©olithique moyen dans la rĂ©gion, qui n’exclut pas les influences extra-europĂ©ennes.The southern Mediterranean Levant has attracted the attention of the scientific community since the early excavations conducted at the beginning of the 20th century on several sites, which provided a significant sample of Upper Pleistocene hominids. Additional skeletal material, circumscribed geographically and chronologically, raises several questions concerning the biological differences and similarities between the hominid samples represented, and their geographical position at the crossroads of Africa and Eurasia. The excellent state of preservation of the hominid remains enables a new insight into the anatomy of Levantine Middle Palaeolithic populations and provides important data for reconstructing the pattern of human evolution in the Near East. With this in view, re-examination of some skeletal remains recovered at Kebara Cave suggests. that biological differences and similarities may have existed between Neanderthals and Levantine Middle Palaeolithic hominids, strengthening the existence of regional variation

    ĐžŃ†Ń–ĐœĐșĐ° яĐșĐŸŃŃ‚Ń– Đ¶ĐžŃ‚Ń‚Ń у ĐČіĐșĐŸĐČох ĐżĐ”Ń€ŃˆĐŸĐČĐ°ĐłŃ–Ń‚ĐœĐžŃ… та ĐČĐ°ĐłŃ–Ń‚ĐœĐžŃ… Đ· ĐČДлОĐșĐžĐŒ Ń–ĐœŃ‚Đ”Ń€ĐłĐ”ĐœĐ”Ń‚ĐžŃ‡ĐœĐžĐŒ Ń–ĐœŃ‚Đ”Ń€ĐČĐ°Đ»ĐŸĐŒ

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    ĐŸŃ€ĐŸĐČĐ”ĐŽĐ”ĐœĐŸ ĐžĐ·ŃƒŃ‡Đ”ĐœĐžĐ” ĐżĐŸĐșазатДлДĐč ĐșачДстĐČĐ° Đ¶ĐžĐ·ĐœĐž у 120 ĐČĐŸĐ·Ń€Đ°ŃŃ‚ĐœŃ‹Ń… пДрĐČĐŸĐ±Đ”Ń€Đ”ĐŒĐ”ĐœĐœŃ‹Ń… Đž 240 Đ±Đ”Ń€Đ”ĐŒĐ”ĐœĐœŃ‹Ń… с Đ±ĐŸĐ»ŃŒŃˆĐžĐŒ ĐžĐœŃ‚Đ”Ń€ĐłĐ”ĐœĐ”Ń‚ĐžŃ‡Đ”ŃĐșĐžĐŒ ĐžĐœŃ‚Đ”Ń€ĐČĐ°Đ»ĐŸĐŒ с ĐžŃĐżĐŸĐ»ŃŒĐ·ĐŸĐČĐ°ĐœĐžĐ”ĐŒ ĐŸĐżŃ€ĐŸŃĐœĐžĐșĐ° SF-36 Health Status Survey, Ń€Đ°Đ·Ń€Đ°Đ±ĐŸŃ‚Đ°ĐœĐœĐŸĐłĐŸ The Health Institute, New England Medical Center, Boston, USA. Đ˜ŃŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐžĐ” ĐżĐŸĐșĐ°Đ·Đ°Đ»ĐŸ, Ń‡Ń‚ĐŸ ĐżĐ°Ń†ĐžĐ”ĐœŃ‚ĐșĐž ĐŸĐ±Đ”ĐžŃ… групп ĐžĐŒĐ”ŃŽŃ‚ ĐœĐžĐ·ĐșОД ĐżĐŸĐșазатДлО ĐșачДстĐČĐ° Đ¶ĐžĐ·ĐœĐž. Про сраĐČĐœĐ”ĐœĐžĐž Đ±ĐŸĐ»ŃŒŃˆĐžĐœŃŃ‚ĐČĐŸ ĐžĐ·ŃƒŃ‡Đ°Đ”ĐŒŃ‹Ń… ĐżĐ°Ń€Đ°ĐŒĐ”Ń‚Ń€ĐŸĐČ ĐŸŃ†Đ”ĐœĐșĐž ĐșачДстĐČĐ° Đ¶ĐžĐ·ĐœĐž ĐČ ĐŸĐ±ŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐœŃ‹Ń… группах ĐœĐ” ĐŸŃ‚Đ»ĐžŃ‡Đ°Đ»ĐžŃŃŒ, ĐŸĐŽĐœĐ°ĐșĐŸ у ĐżĐ°Ń†ĐžĐ”ĐœŃ‚ĐŸĐș с Đ±ĐŸĐ»ŃŒŃˆĐžĐŒ ĐžĐœŃ‚Đ”Ń€ĐłĐ”ĐœĐ”Ń‚ĐžŃ‡Đ”ŃĐșĐžĐŒ ĐžĐœŃ‚Đ”Ń€ĐČĐ°Đ»ĐŸĐŒ – ĐŽĐŸŃŃ‚ĐŸĐČĐ”Ń€ĐœĐŸ ĐČŃ‹ŃˆĐ” ĐŸŃ†Đ”ĐœĐșĐ° ŃĐŸŃ†ĐžĐ°Đ»ŃŒĐœĐŸĐč Ń€ĐŸĐ»Đž Đž ŃĐœĐ”Ń€ĐłĐ”Ń‚ĐžŃ‡ĐœĐŸŃŃ‚Đž. ĐžŃ†Đ”ĐœĐșĐ° ĐșачДстĐČĐ° Đ¶ĐžĐ·ĐœĐž у ĐČĐŸĐ·Ń€Đ°ŃŃ‚ĐœŃ‹Ń… пДрĐČĐŸĐ±Đ”Ń€Đ”ĐŒĐ”ĐœĐœŃ‹Ń… Đž Đ±Đ”Ń€Đ”ĐŒĐ”ĐœĐœŃ‹Ń… с Đ±ĐŸĐ»ŃŒŃˆĐžĐŒ ĐžĐœŃ‚Đ”Ń€ĐłĐ”ĐœĐ”Ń‚ĐžŃ‡Đ”ŃĐșĐžĐŒ ĐžĐœŃ‚Đ”Ń€ĐČĐ°Đ»ĐŸĐŒ яĐČĐ»ŃĐ”Ń‚ŃŃ ĐČĐ°Đ¶ĐœŃ‹ĐŒ ŃĐ”ĐłĐŒĐ”ĐœŃ‚ĐŸĐŒ ĐœĐ°Đ±Đ»ŃŽĐŽĐ”ĐœĐžŃ ĐČĐŸ ĐČŃ€Đ”ĐŒŃ Đ±Đ”Ń€Đ”ĐŒĐ”ĐœĐœĐŸŃŃ‚Đž, ĐșĐŸŃ‚ĐŸŃ€Ń‹Đč ĐŸŃ†Đ”ĐœĐžĐČаДт пДрспДĐșтоĐČы разĐČотоя Đ±Đ”Ń€Đ”ĐŒĐ”ĐœĐœĐŸŃŃ‚Đž ĐČ ĐżŃĐžŃ…ĐŸĐ»ĐŸĐłĐžŃ‡Đ”ŃĐșĐŸĐŒ, фОзОчДсĐșĐŸĐŒ Đž ŃĐŸŃ†ĐžĐ°Đ»ŃŒĐœĐŸĐŒ аспДĐșтах.A study of the life quality of 120 over-age primigravidas and of 240 women with a large intergenetic interval has been carried out using the questionnaire SF-36 Health Status Survey developed by The Health Institute, New England Medical Center, Boston, USA. This research has shown that the patients in the both groups have a low quality of life. The major part of the life quality parameters were the same in the both groups, however, in patients with a large interval between births the values of the social role and the energy level were significantly higher. The life quality of over-age primigravidas and pregnant women with a large interval between successive births is an important sector of observation during pregnancy, which allows assessing the prospects of pregnancy in the psychological, physical, and social aspects

    Predictive factors for severe toxicity of sunitinib in unselected patients with advanced renal cell cancer

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    Sunitinib has been registered for the treatment of advanced renal cell cancer (RCC). As patient inclusion was highly selective in previous studies, experience with sunitinib in general oncological practice remains to be reported. We determined the efficacy and safety of sunitinib in patients with advanced RCC included in an expanded access programme. ECOG performance status >1, histology other than clear cell and presence of brain metastases were no exclusion criteria. Eighty-two patients were treated: 23% reached a partial response, 50% had stable disease, 20% progressed and six patients were not evaluable. Median progression-free survival (PFS) was 9 months and median overall survival (OS) was 15 months. Importantly, 47 patients (57%) needed a dose reduction, 35 (43%) because of treatment-related adverse events, 10 (12%) because of continuous dosing, and two because of both. Stomatitis, fatigue, hand–foot syndrome and a combination of grade 1–2 adverse events were the most frequent reasons for dose reduction. In 40 patients (49%), there was severe toxicity, defined as dose reduction or permanent discontinuation, which was highly correlated with low body surface area, high age and female gender. On the basis of age and gender, a model was developed that could predict the probability of severe toxicity

    New Implications on Genomic Adaptation Derived from the Helicobacter pylori Genome Comparison

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    BACKGROUND: Helicobacter pylori has a reduced genome and lives in a tough environment for long-term persistence. It evolved with its particular characteristics for biological adaptation. Because several H. pylori genome sequences are available, comparative analysis could help to better understand genomic adaptation of this particular bacterium. PRINCIPAL FINDINGS: We analyzed nine H. pylori genomes with emphasis on microevolution from a different perspective. Inversion was an important factor to shape the genome structure. Illegitimate recombination not only led to genomic inversion but also inverted fragment duplication, both of which contributed to the creation of new genes and gene family, and further, homological recombination contributed to events of inversion. Based on the information of genomic rearrangement, the first genome scaffold structure of H. pylori last common ancestor was produced. The core genome consists of 1186 genes, of which 22 genes could particularly adapt to human stomach niche. H. pylori contains high proportion of pseudogenes whose genesis was principally caused by homopolynucleotide (HPN) mutations. Such mutations are reversible and facilitate the control of gene expression through the change of DNA structure. The reversible mutations and a quasi-panmictic feature could allow such genes or gene fragments frequently transferred within or between populations. Hence, pseudogenes could be a reservoir of adaptation materials and the HPN mutations could be favorable to H. pylori adaptation, leading to HPN accumulation on the genomes, which corresponds to a special feature of Helicobacter species: extremely high HPN composition of genome. CONCLUSION: Our research demonstrated that both genome content and structure of H. pylori have been highly adapted to its particular life style

    Direct-coupling analysis of residue co-evolution captures native contacts across many protein families

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    The similarity in the three-dimensional structures of homologous proteins imposes strong constraints on their sequence variability. It has long been suggested that the resulting correlations among amino acid compositions at different sequence positions can be exploited to infer spatial contacts within the tertiary protein structure. Crucial to this inference is the ability to disentangle direct and indirect correlations, as accomplished by the recently introduced Direct Coupling Analysis (DCA) (Weigt et al. (2009) Proc Natl Acad Sci 106:67). Here we develop a computationally efficient implementation of DCA, which allows us to evaluate the accuracy of contact prediction by DCA for a large number of protein domains, based purely on sequence information. DCA is shown to yield a large number of correctly predicted contacts, recapitulating the global structure of the contact map for the majority of the protein domains examined. Furthermore, our analysis captures clear signals beyond intra- domain residue contacts, arising, e.g., from alternative protein conformations, ligand- mediated residue couplings, and inter-domain interactions in protein oligomers. Our findings suggest that contacts predicted by DCA can be used as a reliable guide to facilitate computational predictions of alternative protein conformations, protein complex formation, and even the de novo prediction of protein domain structures, provided the existence of a large number of homologous sequences which are being rapidly made available due to advances in genome sequencing.Comment: 28 pages, 7 figures, to appear in PNA

    Disentangling Direct from Indirect Co-Evolution of Residues in Protein Alignments

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    Predicting protein structure from primary sequence is one of the ultimate challenges in computational biology. Given the large amount of available sequence data, the analysis of co-evolution, i.e., statistical dependency, between columns in multiple alignments of protein domain sequences remains one of the most promising avenues for predicting residues that are contacting in the structure. A key impediment to this approach is that strong statistical dependencies are also observed for many residue pairs that are distal in the structure. Using a comprehensive analysis of protein domains with available three-dimensional structures we show that co-evolving contacts very commonly form chains that percolate through the protein structure, inducing indirect statistical dependencies between many distal pairs of residues. We characterize the distributions of length and spatial distance traveled by these co-evolving contact chains and show that they explain a large fraction of observed statistical dependencies between structurally distal pairs. We adapt a recently developed Bayesian network model into a rigorous procedure for disentangling direct from indirect statistical dependencies, and we demonstrate that this method not only successfully accomplishes this task, but also allows contacts with weak statistical dependency to be detected. To illustrate how additional information can be incorporated into our method, we incorporate a phylogenetic correction, and we develop an informative prior that takes into account that the probability for a pair of residues to contact depends strongly on their primary-sequence distance and the amount of conservation that the corresponding columns in the multiple alignment exhibit. We show that our model including these extensions dramatically improves the accuracy of contact prediction from multiple sequence alignments

    CAGO: A Software Tool for Dynamic Visual Comparison and Correlation Measurement of Genome Organization

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    CAGO (Comparative Analysis of Genome Organization) is developed to address two critical shortcomings of conventional genome atlas plotters: lack of dynamic exploratory functions and absence of signal analysis for genomic properties. With dynamic exploratory functions, users can directly manipulate chromosome tracks of a genome atlas and intuitively identify distinct genomic signals by visual comparison. Signal analysis of genomic properties can further detect inconspicuous patterns from noisy genomic properties and calculate correlations between genomic properties across various genomes. To implement dynamic exploratory functions, CAGO presents each genome atlas in Scalable Vector Graphics (SVG) format and allows users to interact with it using a SVG viewer through JavaScript. Signal analysis functions are implemented using R statistical software and a discrete wavelet transformation package waveslim. CAGO is not only a plotter for generating complex genome atlases, but also a platform for exploring genome atlases with dynamic exploratory functions for visual comparison and with signal analysis for comparing genomic properties across multiple organisms. The web-based application of CAGO, its source code, user guides, video demos, and live examples are publicly available and can be accessed at http://cbs.ym.edu.tw/cago

    Potential pitfalls of modelling ribosomal RNA data in phylogenetic tree reconstruction: Evidence from case studies in the Metazoa

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    <p>Abstract</p> <p>Background</p> <p>Failure to account for covariation patterns in helical regions of ribosomal RNA (rRNA) genes has the potential to misdirect the estimation of the phylogenetic signal of the data. Furthermore, the extremes of length variation among taxa, combined with regional substitution rate variation can mislead the alignment of rRNA sequences and thus distort subsequent tree reconstructions. However, recent developments in phylogenetic methodology now allow a comprehensive integration of secondary structures in alignment and tree reconstruction analyses based on rRNA sequences, which has been shown to correct some of these problems. Here, we explore the potentials of RNA substitution models and the interactions of specific model setups with the inherent pattern of covariation in rRNA stems and substitution rate variation among loop regions.</p> <p>Results</p> <p>We found an explicit impact of RNA substitution models on tree reconstruction analyses. The application of specific RNA models in tree reconstructions is hampered by interaction between the appropriate modelling of covarying sites in stem regions, and excessive homoplasy in some loop regions. RNA models often failed to recover reasonable trees when single-stranded regions are excessively homoplastic, because these regions contribute a greater proportion of the data when covarying sites are essentially downweighted. In this context, the RNA6A model outperformed all other models, including the more parametrized RNA7 and RNA16 models.</p> <p>Conclusions</p> <p>Our results depict a trade-off between increased accuracy in estimation of interdependencies in helical regions with the risk of magnifying positions lacking phylogenetic signal. We can therefore conclude that caution is warranted when applying rRNA covariation models, and suggest that loop regions be independently screened for phylogenetic signal, and eliminated when they are indistinguishable from random noise. In addition to covariation and homoplasy, other factors, like non-stationarity of substitution rates and base compositional heterogeneity, can disrupt the signal of ribosomal RNA data. All these factors dictate sophisticated estimation of evolutionary pattern in rRNA data, just as other molecular data require similarly complicated (but different) corrections.</p
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