620 research outputs found
The frequency and pattern of dental caries in archaeological populations from Estonia
The caries rate is an important indicator of dental health but also provides a lot of information about dietary habits and the lifestyle of past populations. To understand dietary changes, it is important to observe both the primary location and the severity of caries lesions.In the present study the prevalence, location and severity of caries lesions were recorded on 5,838 teeth of six skeletal populations from Estonia, from the Migration Period (450–600 AD) to the Early Modern Times (18. c.).Scoring of the presence and location of caries was done visually with the aid of a dental probe in all the observable teeth.The majority of dental caries appeared at the cemento-enamel junction, or the appositional surfaces in all the groups. The frequency of caries as well as the severity of lesions increased gradually from the Migration Period to the Early Modern Period. No severe caries lesions (to the pulp) were registered in the Migration Period, and in the Early Modern Times 27% of caries lesions were penetrating to the pulp chamber.These differences in the frequency and the pattern of caries distribution show possible dietary and subsistence differences between groups. The distribution, as well as the overall prevalence of cavities, suggest that in later periods the diet was probably more cariogenic and less abrasive
Conventional ageing and sexing methods based on teeth and dry bone morphology in the person’s identification (victims of red terror in 1946)
Human skeletal remains exhumated from the post-war multiple grave in Southern Estonia were anthropologically analysed. Conventional ageing and sexing methods were used to esimate biological sex and age at death of buried people. The blind test was carried out by two independent researchers; the obtained results were compared with historic data concerning the chronological age at death and the sex of buried people
The content of chemical elements in archaeological human bones as a source of nutrition research
The aim of the present research was to determine chemical elements using the inductive plasma mass spectrometer (ICP-MS) in Estonian archaeological human bones to establish the possible content of the menu in different communities. Among the studied material clear differentiation can be made between the Pärnu cemetery of St John’s church (the cemetery of the Pärnu garrison) from the 16–18th cc. and the Tääksi village cemetery from the 14–18th century. The material from the 12–13th cc. Pada cemetery remains between the two above-mentioned cemeteries concerning the content of the observed elements. The initial data show only the differences of the general trends of the content of chemical elements between the inland and the coastal areas, the village and the town, the higher and the lower social status communities. The contents of chemical elements in the Estonian archaeological bones were similar to the respective contents in Latvia
Gender equality and investments in adolescents in the rural Philippines:
"...Many studies have looked at the way resources are distributed to men, women, and especially to small children, but one age group within the family has been largely ignored: the adolescents. Adolescence is a crucial period in that teenagers can make major contributions to their families' welfare through their labor and earnings, in and outside the household, but may sacrifice their own wishes and future well-being in the process if such contributions come at the expense of investments in their education. The research methodology in this report, combining regression analysis with ethnography, provides a lesson in how complementarities between methodological approaches can be exploited...The research finds that parents are not unduly influenced by short-term needs and are ready to make substantial sacrifices in terms of current consumption in order to invest in their children's future. The research also concludes that boys and girls in this rural area of the Philippines are generally treated equally, provid ing a contrast with other Asian settings where discrimination by gender is common." (Forward by Per Pinstrup- Andersen)Teenagers Philippines Social conditions., Rural families Philippines., Gender, Health and nutrition, Education Economic aspects Philippines., Household resource allocation, Health.,
Elaboración del aceite en la provincia de Jaén
En número dedicado a: La provincia de Jaé
第7章 平成22年度~24年度特別研究 : 「地域歴史遺産保全活用教育研究を基軸とした地域歴史文化育成支援拠点の整備」事業
textabstractThe Mre11 complex (Mre11-Rad50-Nbs1 or MRN) binds double-strand breaks where it interacts with CtIP/Ctp1/Sae2 and ATM/Tel1 to preserve genome stability through its functions in homology-directed repair, checkpoint signaling and telomere maintenance. Here, we combine biochemical, structural and in vivo functional studies to uncover key properties of Mre11-W243R, a mutation identified in two pediatric cancer patients with enhanced ataxia telangiectasia-like disorder. Purified human Mre11-W243R retains nuclease and DNA binding activities in vitro. X-ray crystallography of Pyrococcus furiosus Mre11 indicates that an analogous mutation leaves the overall Mre11 threedimensional structure and nuclease sites intact but disorders surface loops expected to regulate DNA and Rad50 interactions. The equivalent W248R allele in fission yeast allows Mre11 to form an MRN complex that efficiently binds double-strand breaks, activates Tel1/ATM and maintains telomeres; yet, it causes hypersensitivity to ionizing radiation and collapsed replication forks, increased Rad52 foci, defective Chk1 signaling and meiotic failure. W248R differs from other ataxia telangiectasia-like disorder analog alleles by the reduced stability of its interaction with Rad50 in cell lysates. Collective results suggest a separation-of-function mutation that disturbs interactions amongst the MRN subunits and Ctp1 required for DNA end processing in vivo but maintains interactions sufficient for Tel1/ATM checkpoint and telomere maintenance functions
Distinct requirements for the Rad32(Mre¹¹) nuclease and Ctp1(CtIP) in the removal of covalently bound topoisomerase I and II from DNA
For a cancer cell to resist treatment with drugs that trap topoisomerases covalently on the DNA, the topoisomerase must be removed. In this study, we provide evidence that the Schizosaccharomyces pombe Rad32Mre11 nuclease activity is involved in the removal of both Top2 from 5′ DNA ends as well as Top1 from 3′ ends in vivo. A ctp1CtIP deletion is defective for Top2 removal but overproficient for Top1 removal, suggesting that Ctp1CtIP plays distinct roles in removing topoisomerases from 5′ and 3′ DNA ends. Analysis of separation of function mutants suggests that MRN-dependent topoisomerase removal contributes significantly to resistance against topoisomerase-trapping drugs. This study has important implications for our understanding of the role of the MRN complex and CtIP in resistance of cells to a clinically important group of anticancer drugs
Checkpoints are blind to replication restart and recombination intermediates that result in gross chromosomal rearrangements
Replication fork inactivation can be overcome by homologous recombination, but this can cause gross chromosomal rearrangements that subsequently missegregate at mitosis, driving further chromosome instability. It is unclear when the chromosome rearrangements are generated and whether individual replication problems or the resulting recombination intermediates delay the cell cycle. Here we have investigated checkpoint activation during HR-dependent replication restart using a site-specific replication fork-arrest system. Analysis during a single cell cycle shows that HR-dependent replication intermediates arise in S phase, shortly after replication arrest, and are resolved into acentric and dicentric chromosomes in G2. Despite this, cells progress into mitosis without delay. Neither the DNA damage nor the intra-S phase checkpoints are activated in the first cell cycle, demonstrating that these checkpoints are blind to replication and recombination intermediates as well as to rearranged chromosomes. The dicentrics form anaphase bridges that subsequently break, inducing checkpoint activation in the second cell cycle
An essential function for the ATR-Activation-Domain (AAD) of TopBP1 in mouse development and cellular senescence
ATR activation is dependent on temporal and spatial interactions with partner proteins. In the budding yeast model, three proteins – Dpb11TopBP1, Ddc1Rad9 and Dna2 - all interact with and activate Mec1ATR. Each contains an ATR activation domain (ADD) that interacts directly with the Mec1ATR:Ddc2ATRIP complex. Any of the Dpb11TopBP1, Ddc1Rad9 or Dna2 ADDs is sufficient to activate Mec1ATR in vitro. All three can also independently activate Mec1ATR in vivo: the checkpoint is lost only when all three AADs are absent. In metazoans, only TopBP1 has been identified as a direct ATR activator. Depletion-replacement approaches suggest the TopBP1-AAD is both sufficient and necessary for ATR activation. The physiological function of the TopBP1 AAD is, however, unknown. We created a knock-in point mutation (W1147R) that ablates mouse TopBP1-AAD function. TopBP1-W1147R is early embryonic lethal. To analyse TopBP1-W1147R cellular function in vivo, we silenced the wild type TopBP1 allele in heterozygous MEFs. AAD inactivation impaired cell proliferation, promoted premature senescence and compromised Chk1 signalling following UV irradiation. We also show enforced TopBP1 dimerization promotes ATR-dependent Chk1 phosphorylation. Our data suggest that, unlike the yeast models, the TopBP1-AAD is the major activator of ATR, sustaining cell proliferation and embryonic development
Manufacturing of Food Packaging Based on Nanocellulose : Current Advances and Challenges
Nowadays, environmental pollution due to synthetic polymers represents one of the biggest worldwide challenges. As demonstrated in numerous scientific articles, plant-based nanocellulose (NC) is a biodegradable and nontoxic material whose mechanical, rheological, and gas barrier properties are competitive compared to those of oil-based plastics. However, the sensitivity of NC in humid ambient and lack of thermosealability have proven to be a major obstacle that hinders its breakthrough in various sectors including food packaging. In recent years, attempts have been made in order to provide a hydrophobic character to NC through chemical modifications. In addition, extensive works on nanocellulose applications in food packaging such as coating, layer-by-layer, casting, and electrospinning have been reported. Despite these enormous advances, it can easily be observed that packaging manufacturers have not yet shown a particular interest in terms of applicability and processability of the nanocellulose due to the lack of guidelines and guarantee on the success of their implementation. This review is useful for researchers and packaging manufacturers because it puts emphasis on recent works that have dealt with the nanocellulose applications and focuses on the best strategies to be adopted for swift and sustainable industrial manufacturing scale-up of high-performance bio-based/compostable packaging in replacement of the oil-based counterparts used today
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