221 research outputs found
Identité biologique des artisans moustériens de Kebara (Mont Carmel, Israël) Réflexions sur le concept de néanderthalien au Levant méditerranéen
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, lâenrichissement 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 lâoriginalitĂ© de lâassemblage de caractĂšres anatomiques prĂ©sents ne doit pas ĂȘtre sous-estimĂ©e pour une meilleure Ă©valuation des composantes rĂ©gionales. Câest ce qui est proposĂ© Ă propos de Kebara, lâobjectif Ă©tant de favoriser une approche cohĂ©rente de la diversitĂ© biologique des hommes du PalĂ©olithique moyen dans la rĂ©gion, qui nâexclut 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
Evolutionary Analysis of Mitogenomes from Parasitic and Free-Living Flatworms
Copyright: © 2015 SolĂ et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article
ĐŃŃĐœĐșĐ° ŃĐșĐŸŃŃŃ Đ¶ĐžŃŃŃ Ń ĐČŃĐșĐŸĐČĐžŃ ĐżĐ”ŃŃĐŸĐČĐ°ĐłŃŃĐœĐžŃ ŃĐ° ĐČĐ°ĐłŃŃĐœĐžŃ Đ· ĐČДлОĐșĐžĐŒ ŃĐœŃĐ”ŃĐłĐ”ĐœĐ”ŃĐžŃĐœĐžĐŒ ŃĐœŃĐ”ŃĐČĐ°Đ»ĐŸĐŒ
ĐŃĐŸĐČĐ”ĐŽĐ”ĐœĐŸ ОзŃŃĐ”ĐœĐžĐ” ĐżĐŸĐșĐ°Đ·Đ°ŃДлДĐč ĐșĐ°ŃĐ”ŃŃĐČĐ° Đ¶ĐžĐ·ĐœĐž Ń 120 ĐČĐŸĐ·ŃĐ°ŃŃĐœŃŃ
пДŃĐČĐŸĐ±Đ”ŃĐ”ĐŒĐ”ĐœĐœŃŃ
Đž 240 бДŃĐ”ĐŒĐ”ĐœĐœŃŃ
Ń Đ±ĐŸĐ»ŃŃĐžĐŒ ĐžĐœŃĐ”ŃĐłĐ”ĐœĐ”ŃĐžŃĐ”ŃĐșĐžĐŒ ĐžĐœŃĐ”ŃĐČĐ°Đ»ĐŸĐŒ Ń ĐžŃĐżĐŸĐ»ŃĐ·ĐŸĐČĐ°ĐœĐžĐ”ĐŒ ĐŸĐżŃĐŸŃĐœĐžĐșĐ° SF-36 Health Status Survey,
ŃĐ°Đ·ŃĐ°Đ±ĐŸŃĐ°ĐœĐœĐŸĐłĐŸ The Health Institute, New England Medical Center, Boston, USA. ĐŃŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐžĐ” ĐżĐŸĐșĐ°Đ·Đ°Đ»ĐŸ, ŃŃĐŸ
паŃĐžĐ”ĐœŃĐșĐž ĐŸĐ±Đ”ĐžŃ
ĐłŃŃпп ĐžĐŒĐ”ŃŃ ĐœĐžĐ·ĐșОД ĐżĐŸĐșĐ°Đ·Đ°ŃДлО ĐșĐ°ŃĐ”ŃŃĐČĐ° Đ¶ĐžĐ·ĐœĐž. ĐŃĐž ŃŃĐ°ĐČĐœĐ”ĐœĐžĐž Đ±ĐŸĐ»ŃŃĐžĐœŃŃĐČĐŸ ОзŃŃĐ°Đ”ĐŒŃŃ
паŃĐ°ĐŒĐ”ŃŃĐŸĐČ ĐŸŃĐ”ĐœĐșĐž ĐșĐ°ŃĐ”ŃŃĐČĐ° Đ¶ĐžĐ·ĐœĐž ĐČ ĐŸĐ±ŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐœŃŃ
ĐłŃŃппаŃ
ĐœĐ” ĐŸŃлОŃалОŃŃ, ĐŸĐŽĐœĐ°ĐșĐŸ Ń ĐżĐ°ŃĐžĐ”ĐœŃĐŸĐș Ń Đ±ĐŸĐ»ŃŃĐžĐŒ
ĐžĐœŃĐ”ŃĐłĐ”ĐœĐ”ŃĐžŃĐ”ŃĐșĐžĐŒ ĐžĐœŃĐ”ŃĐČĐ°Đ»ĐŸĐŒ â ĐŽĐŸŃŃĐŸĐČĐ”ŃĐœĐŸ ĐČŃŃĐ” ĐŸŃĐ”ĐœĐșĐ° ŃĐŸŃОалŃĐœĐŸĐč ŃĐŸĐ»Đž Đž ŃĐœĐ”ŃгДŃĐžŃĐœĐŸŃŃĐž.
ĐŃĐ”ĐœĐșĐ° ĐșĐ°ŃĐ”ŃŃĐČĐ° Đ¶ĐžĐ·ĐœĐž Ń ĐČĐŸĐ·ŃĐ°ŃŃĐœŃŃ
пДŃĐČĐŸĐ±Đ”ŃĐ”ĐŒĐ”ĐœĐœŃŃ
Đž бДŃĐ”ĐŒĐ”ĐœĐœŃŃ
Ń Đ±ĐŸĐ»ŃŃĐžĐŒ ĐžĐœŃĐ”ŃĐłĐ”ĐœĐ”ŃĐžŃĐ”ŃĐșĐžĐŒ
ĐžĐœŃĐ”ŃĐČĐ°Đ»ĐŸĐŒ ŃĐČĐ»ŃĐ”ŃŃŃ ĐČĐ°Đ¶ĐœŃĐŒ ŃĐ”ĐłĐŒĐ”ĐœŃĐŸĐŒ ĐœĐ°Đ±Đ»ŃĐŽĐ”ĐœĐžŃ ĐČĐŸ ĐČŃĐ”ĐŒŃ Đ±Đ”ŃĐ”ĐŒĐ”ĐœĐœĐŸŃŃĐž, ĐșĐŸŃĐŸŃŃĐč ĐŸŃĐ”ĐœĐžĐČĐ°Đ”Ń
пДŃŃпДĐșŃĐžĐČŃ ŃĐ°Đ·ĐČĐžŃĐžŃ Đ±Đ”ŃĐ”ĐŒĐ”ĐœĐœĐŸŃŃĐž ĐČ ĐżŃĐžŃ
ĐŸĐ»ĐŸĐłĐžŃĐ”ŃĐșĐŸĐŒ, ŃОзОŃĐ”ŃĐșĐŸĐŒ Đž ŃĐŸŃОалŃĐœĐŸĐŒ Đ°ŃпДĐșŃĐ°Ń
.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
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SEIS: Insight's Seismic Experiment for Internal Structure of Mars.
By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars' surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking's Mars seismic monitoring by a factor of ⌠2500 at 1 Hz and ⌠200 000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars' surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of M w ⌠3 at 40 â epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution.Electronic supplementary materialThe online version of this article (10.1007/s11214-018-0574-6) contains supplementary material, which is available to authorized users
Charge and current-sensitive preamplifiers for pulse shape discrimination techniques with silicon detectors
New charge and current-sensitive preamplifiers coupled to silicon detectors
and devoted to studies in nuclear structure and dynamics have been developed
and tested. For the first time shapes of current pulses from light charged
particles and carbon ions are presented. Capabilities for pulse shape
discrimination techniques are demonstrated.Comment: 14 pages, 12 figures, to be published in Nucl. Inst. Meth.
Molecular Phylogenetic Evaluation of Classification and Scenarios of Character Evolution in Calcareous Sponges (Porifera, Class Calcarea)
Calcareous sponges (Phylum Porifera, Class Calcarea) are known to be taxonomically difficult. Previous molecular studies have revealed many discrepancies between classically recognized taxa and the observed relationships at the order, family and genus levels; these inconsistencies question underlying hypotheses regarding the evolution of certain morphological characters. Therefore, we extended the available taxa and character set by sequencing the complete small subunit (SSU) rDNA and the almost complete large subunit (LSU) rDNA of additional key species and complemented this dataset by substantially increasing the length of available LSU sequences. Phylogenetic analyses provided new hypotheses about the relationships of Calcarea and about the evolution of certain morphological characters. We tested our phylogeny against competing phylogenetic hypotheses presented by previous classification systems. Our data reject the current order-level classification by again finding non-monophyletic Leucosolenida, Clathrinida and Murrayonida. In the subclass Calcinea, we recovered a clade that includes all species with a cortex, which is largely consistent with the previously proposed order Leucettida. Other orders that had been rejected in the current system were not found, but could not be rejected in our tests either. We found several additional families and genera polyphyletic: the families Leucascidae and Leucaltidae and the genus Leucetta in Calcinea, and in Calcaronea the family Amphoriscidae and the genus Ute. Our phylogeny also provided support for the vaguely suspected close relationship of several members of Grantiidae with giantortical diactines to members of Heteropiidae. Similarly, our analyses revealed several unexpected affinities, such as a sister group relationship between Leucettusa (Leucaltidae) and Leucettidae and between Leucascandra (Jenkinidae) and Sycon carteri (Sycettidae). According to our results, the taxonomy of Calcarea is in desperate need of a thorough revision, which cannot be achieved by considering morphology alone or relying on a taxon sampling based on the current classification below the subclass level
New Implications on Genomic Adaptation Derived from the Helicobacter pylori Genome Comparison
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
MSH3 polymorphisms and protein levels affect CAG repeat instability in huntington's disease mice
Expansions of trinucleotide CAG/CTG repeats in somatic tissues are thought to contribute to ongoing disease progression through an affected individual's life with Huntington's disease or myotonic dystrophy. Broad ranges of repeat instability arise between individuals with expanded repeats, suggesting the existence of modifiers of repeat instability. Mice with expanded CAG/CTG repeats show variable levels of instability depending upon mouse strain. However, to date the genetic modifiers underlying these differences have not been identified. We show that in liver and striatum the R6/1 Huntington's disease (HD) (CAG)~100 transgene, when present in a congenic C57BL/6J (B6) background, incurred expansion-biased repeat mutations, whereas the repeat was stable in a congenic BALB/cByJ (CBy) background. Reciprocal congenic mice revealed the Msh3 gene as the determinant for the differences in repeat instability. Expansion bias was observed in congenic mice homozygous for the B6 Msh3 gene on a CBy background, while the CAG tract was stabilized in congenics homozygous for the CBy Msh3 gene on a B6 background. The CAG stabilization was as dramatic as genetic deficiency of Msh2. The B6 and CBy Msh3 genes had identical promoters but differed in coding regions and showed strikingly different protein levels. B6 MSH3 variant protein is highly expressed and associated with CAG expansions, while the CBy MSH3 variant protein is expressed at barely detectable levels, associating with CAG stability. The DHFR protein, which is divergently transcribed from a promoter shared by the Msh3 gene, did not show varied levels between mouse strains. Thus, naturally occurring MSH3 protein polymorphisms are modifiers of CAG repeat instability, likely through variable MSH3 protein stability. Since evidence supports that somatic CAG instability is a modifier and predictor of disease, our data are consistent with the hypothesis that variable levels of CAG instability associated with polymorphisms of DNA repair genes may have prognostic implications for various repeat-associated diseases
Potential pitfalls of modelling ribosomal RNA data in phylogenetic tree reconstruction: Evidence from case studies in the Metazoa
<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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