2,159 research outputs found
Upscaling of a dual-permeability Monte Carlo simulation model for contaminant transport in fractured networks by genetic algorithm parameter identification
International audienceThe transport of radionuclides in fractured media plays a fundamental role in determining the level of risk offered by a radioactive waste repository in terms of expected doses. Discrete Fracture Networks (DFN) methods can provide detailed solutions to the problem of modeling the contaminant transport in fractured media. However, within the framework of the performance assessment (PA) of radioactive waste repositories, the computational efforts required are not compatible with the repeated calculations that need to be performed for the probabilistic uncertainty and sensitivity analyses of PA. In this paper, we present a novel upscaling approach, which consists in computing the detailed numerical fractured flow and transport solutions on a small scale and use the results to derive the equivalent continuum parameters of a lean, one-dimensional Dual-Permeability, Monte Carlo Simulation (DPMCS) model by means of a Genetic Algorithm search. The proposed upscaling procedure is illustrated with reference to a realistic case study of migration taken from literature
Altered deoxyribonucleotide pools in T-lymphoblastoid cells expressing the multisubstrate nucleoside kinase of Drosophila melanogaster
The multisubstrate nucleoside kinase of Drosophila melanogaster (Dm-dNK) can be expressed in human solid tumor cells and its unique enzymatic properties makes this enzyme a suicide gene candidate. In the present study, Dm-dNK was stably expressed in the CCRF-CEM and H9 T-lymphoblastoid cell lines. The expressed enzyme was localized to the cell nucleus and the enzyme retained its activity. The Dm-dNK overexpressing cells showed approximately 200-fold increased sensitivity to the cytostatic activity of several nucleoside analogs, such as the pyrimidine nucleoside analogs (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) and 1-beta-d-arabinofuranosylthymine (araT), but not to the antiherpetic purine nucleoside analogs ganciclovir, acyclovir and penciclovir, which may allow this technology to be applied in donor T cells and/or rescue graft vs. host disease to permit modulation of alloreactivity after transplantation. The most pronounced effect on the steady-state dNTP levels was a two- to 10-fold increased dTTP pool in Dm-dNK expressing cells that were grown in the presence of 1 microm of each natural deoxyribonucleoside. Although the Dm-dNK expressing cells demonstrated dNTP pool imbalances, no mitochondrial DNA deletions or altered mitochondrial DNA levels were detected in the H9 Dm-dNK expressing cells
JUROS POR DENTRO E A MATEMÁTICA FINANCEIRA NO ENSINO MÉDIO
Esta dissertação é um estudo que envolve a Matemática Financeira, dando destaque aos
sistemas de financiamento e dos Juros por Dentro, assuntos importantes para o ensino
da Matemática, porém pouco explorado ao longo do Ensino Médio nas escolas do
Brasil. O objetivo do trabalho é fornecer um material que sirva de auxilio para o
professor do ensino básico, no que tange ao desenvolvimento de suas aulas que
envolvam os temas da Matemática Financeira, como os sistemas de juros simples e
compostos, bem como os sistemas de financiamento SAC e PRICE. Ademais,
analisamos como são taxados os encargos dos impostos na conta de luz, no cálculo do
ICMS e no sistema de precificação denominado MARKUP, evidenciando o sistema de
juros por dentro, tema pouco conhecido até mesmo por estudantes da área. Esta análise
é importante não apenas para o ensino da Matemática em si, mas também como
informação para a população em geral, já que trata-se de um tema que está inserido no
cotidiano das pessoas. Para a elaboração dessa pesquisa, foram consultadas contas de
luz da cidade de Vila Velha ES e a cartilha fornecida pela ANEEL, que orienta como
deve ser feito o cálculo do valor da conta de luz. Percebemos, ao longo do estudo, que o
modo de cálculo por dentro eleva drasticamente o valor pago pelo consumidor, seja da
conta de luz ou de algum produto do mercado
Sustained E2F-Dependent Transcription Is a Key Mechanism to Prevent Replication-Stress-Induced DNA Damage
Recent work established DNA replication stress as a crucial driver of genomic instability and a key event at the onset of cancer. Post-translational modifications play an important role in the cellular response to replication stress by regulating the activity of key components to prevent replication-stress-induced DNA damage. Here, we establish a far greater role for transcriptional control in determining the outcome of replication-stress-induced events than previously suspected. Sustained E2F-dependent transcription is both required and sufficient for many crucial checkpoint functions, including fork stalling, stabilization, and resolution. Importantly, we also find that, in the context of oncogene-induced replication stress, where increased E2F activity is thought to cause replication stress, E2F activity is required to limit levels of DNA damage. These data suggest a model in which cells experiencing oncogene-induced replication stress through deregulation of E2F-dependent transcription become addicted to E2F activity to cope with high levels of replication stress
Adding Evidence to the Role of NEUROG1 in Congenital Cranial Dysinnervation Disorders
Congenital cranial dysinnervation disorders (CCDDs) are a heterogeneous group of neurodevelopmental phenotypes caused by a primary disturbance of innervation due to deficient, absent, or misguided cranial nerves. Although some CCDDs genes are known, several clinical phenotypes and their aetiologies remain to be elucidated. We describe a 12-year-old boy with hypotonia, developmental delay, sensorineural hearing loss, and keratoconjunctivitis due to lack of corneal reflex. He had a long expressionless face, severe oromotor dysfunction, bilateral agenesis/severe hypoplasia of the VIII nerve with marked atresia of the internal auditory canals and cochlear labyrinth malformation. Trio-exome sequencing identified a homozygous loss of function variant in the NEUROG1 gene (NM_006161.2: c.202G > T, p.Glu68*). NEUROG1 is considered a causal candidate for CCDDs based on (i) the previous report of a patient with a homozygous gene deletion and developmental delay, deafness due to absent bilateral VIII nerves, and severe oromotor dysfunction; (ii) a second patient with a homozygous NEUROG1 missense variant and corneal opacity, absent corneal reflex and intellectual disability; and (iii) the knockout mouse model phenotype which highly resembles the disorder observed in humans. Our findings support the growing compelling evidence that loss of NEUROG1 leads to a very distinctive disorder of cranial nerves development.info:eu-repo/semantics/publishedVersio
Recent Ostracod Fauna of the Western Ross Sea (Antarctica): A Poorly Known Ingredient of Polar Carbonate Factories
Ostracoda are a minor but recurrent component of Southern Ocean marine carbonate factories, and their low-Mg calcitic skeletal mineralogy helps in ensuring a noteworthy post-mortem resilience. Our study, based upon surface sediment occurrences, contributes to the better definition of their distribution vs. potential controlling factors in Antarctic waters. The ostracod fauna from the Western Ross Sea Shelf appears dominated by Australicythere polylyca, Australicythere devexa, Xestoleberis rigusa, Loxoreticulatum fallax, Cativella bensoni, Austrotrachyleberis antarctica and Patagonacythere longiducta, colonizing a variety of shelf environments along a wide bathymetric range. The abundance and richness values correlate well to nutrient distribution and sediment supply, primarily related to the circulation of different oceanographic regimes affecting the floor of the Ross Sea Shelf. Circumpolar Deep Water could represent the main factor controlling the distribution of ostracods. Similar results (high abundance and richness in ostracod values) were also recorded in the Terra Nova Bay and in a nearby area characterized by warm water rich in nutrients and composed of water of circumpolar origin flowing from the open ocean southwards onto the continental shelf. Particulate Fe (pFe), in suspended particulate matter (SPM), and other particulate trace metals in TNB could support the hypothesis that biogenic iron may significantly contribute to the bioavailable iron pool, sustaining both primary production and ostracod fauna richness in this area
Certified Computer Algebra on top of an Interactive Theorem Prover
Contains fulltext :
35027.pdf (publisher's version ) (Open Access
Pica for Uncooked Basmati Rice in Two Women with Iron Deficiency and a Review of Ryzophagia
Reports of pica for uncooked rice (ryzophagia) in adults who reside in European and derivative countries are uncommon. We evaluated and treated two nonpregnant women with pica for uncooked basmati rice. Both women reported fatigue, abdominal discomfort after consuming large quantities of uncooked basmati rice, and hair loss. One woman was from India and the other was from Pakistan. Both women were vegetarians. Basmati was the local rice in their native countries and their usual rice in the USA. Both women had tooth damage due to eating uncooked rice and iron deficiency with microcytic anemia attributed to menorrhagia and multiparity. Ryzophagia and other manifestations (except tooth damage) resolved after iron dextran therapy. We review and discuss other reports of ryzophagia associated with iron deficiency, pregnancy, race/ethnicity, geographic origin, and local traditions. We conclude that adults with ryzophagia in European and derivative countries are likely to be non-Europeans
The camera of the fifth H.E.S.S. telescope. Part I: System description
In July 2012, as the four ground-based gamma-ray telescopes of the H.E.S.S.
(High Energy Stereoscopic System) array reached their tenth year of operation
in Khomas Highlands, Namibia, a fifth telescope took its first data as part of
the system. This new Cherenkov detector, comprising a 614.5 m^2 reflector with
a highly pixelized camera in its focal plane, improves the sensitivity of the
current array by a factor two and extends its energy domain down to a few tens
of GeV.
The present part I of the paper gives a detailed description of the fifth
H.E.S.S. telescope's camera, presenting the details of both the hardware and
the software, emphasizing the main improvements as compared to previous
H.E.S.S. camera technology.Comment: 16 pages, 13 figures, accepted for publication in NIM
Complete genome sequences of two Helicobacter pylori strains from a Canadian Arctic Aboriginal community
We report here the complete genome sequences of two Amerind Helicobacter pylori strains from Aklavik, Northwest Territories, Canada. One strain contains extra iron-cofactored urease genes and ~140 rearrangements in its chromosome relative to other described strains (typically differing from one another by <10 rearrangements), suggesting that it represents a novel lineage of H. pylori
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