385 research outputs found
Triplet repeats form secondary structures that escape DNA repair in yeast
Several human neurodegenerative diseases result from expansion of CTG/CAG or CGG/CCG triplet repeats. The finding that single-stranded CNG repeats form hairpin-like structures in vitro has led to the hypothesis that DNA secondary structure formation is an important component of the expansion mechanism. We show that single-stranded DNA loops containing 10 CTG/CAG or CGG/CCG repeats are inefficiently repaired during meiotic recombination in Saccharomyces cerevisiae. Comparisons of the repair of DNA loops with palindromic and nonpalindromic sequences suggest that this inefficient repair reflects the ability of these sequences to form hairpin structures in vivo
Large-scale geo-facial image analysis
While face analysis from images is a well-studied area, little work has explored the dependence of facial appearance on the geographic location from which the image was captured. To fill this gap, we constructed GeoFaces, a large dataset of geotagged face images, and used it to examine the geo-dependence of facial features and attributes, such as ethnicity, gender, or the presence of facial hair. Our analysis illuminates the relationship between raw facial appearance, facial attributes, and geographic location, both globally and in selected major urban areas. Some of our experiments, and the resulting visualizations, confirm prior expectations, such as the predominance of ethnically Asian faces in Asia, while others highlight novel information that can be obtained with this type of analysis, such as the major city with the highest percentage of people with a mustache
Accretion physics at high X-ray spectral resolution: New frontiers and game-changing science
Microcalorimeters have demonstrated success in delivering high spectral
resolution, and have paved the path to revolutionary new science possibilities
in the coming decade of X-ray astronomy. There are several research areas in
compact object science that can only be addressed with energy resolution
Delta(E)<~5 eV at photon energies of a few keV, corresponding to velocity
resolution of <~a few hundred km/s, to be ushered in by microcalorimeters.
Here, we review some of these outstanding questions, focusing on how the
research landscape is set to be transformed (i) at the interface between
accreting supermassive black holes and their host galaxies, (ii) in unravelling
the structures of accretion environments, (iii) in resolving long-standing
issues on the origins of energy and matter feedback, and (iv) to test
mass-scaled unification of accretion and feedback. The need to learn lessons
from Hitomi and to make improvements in laboratory atomic data precision as
well as plasma modeling are highlighted.Comment: To appear in Nature Astronomy as a review. Author version, before
final editorial and style revision
International round-robin experiment for angle-resolved light scattering measurement
International audienc
How Visitors and Locals at a Sport Event Differ in Motives and Identity
Although the literature on events differentiates between locals, casual attendees, and those who have travelled specifically to attend the event, little is known about how the types of attendee differ. This study compared the fan motivation, leisure motivation, and identification with the subculture of athletics reported by a sample (N = 777) of attendees at the 2005 Pan American Junior Athletics Championships. Age, gender, and income were also included. Regression analyses were used to determine the structure of relations among the variables, and to ascertain whether the levels of motivation or identity varied among the three types of attendee. Tests for linear restrictions were used to determine whether the structure of relations among the variables differed by type of attendee. The structure of relations among the variables did not differ among the three types of attendee, but attendees who had travelled specifically to attend the event reported substantially higher identification with the subculture of athletics, and slightly higher fan motivation. Identification with the subculture of athletics mediated much of the effect. Females reported higher fan motivation and higher leisure motivation than did males. Age had a small but significant relationship with fan motivation, and income had a small but significant relationship with leisure motivation. Findings are generally consistent with predictions derived from theories of motivation, subculture, and gender roles. It is suggested that marketing communications directed out-of-town should highlight opportunities to strengthen, parade, and celebrate, while those in the local trading radius should underscore the entertainment, aesthetics, and vicarious achievement featured at the event
Fluorescence in-situ hybridisation on biopsies from clam ileocystoplasties and on a clam cancer
The incidence of carcinoma following an enterocystoplasty increases with time and is a major concern after such procedures. The aim of this study was to investigate genetic instability (in the form of numerical chromosomal aberrations) at the enterovesical anastomosis in patients who had undergone a clam ileocystoplasty using fluorescent in-situ hybridisation (FISH). Fluorescent in-situ hybridisation was performed on touch preparation samples prepared from fresh endoscopic biopsies obtained from the enterovesical anastomosis and native bladder remnant (control specimens) of 15 patients who had undergone a clam ileocystoplasty. Fluorescent in-situ hybridisation was also performed on one squamous cell cancer specimen. Significant aneusomic changes were found at the enterovesical anastomosis in all 15 patients. Alterations in chromosome 18 copy number were the most frequent abnormal finding (trisomy 18, n=8; monosomy 18, n=7). Nine patients were monosomic for chromosome 9. Isolated monosomy 8 and trisomy 8 were each found in one patient. The control specimens were all normal. An unusually high incidence of polysomic cells was found in the clam tumour specimen, reflecting the aggressive nature of this cancer. Chromosomal numerical abnormalities occur at the enterovesical anastomosis following a clam ileocystoplasty and chromosome 18 appears to be a particularly good marker of genetic instability. The results of this study indicate that morphologically normal tissue obtained from the enterovesical anastomosis displays evidence of chromosomal instability that may predispose to tumour formation. However, further prospective, blinded, longitudinal studies are required to establish whether predetermined FISH signal patterns in enterocystoplasty cells in urine or obtained by biopsy predict the presence or absence of tumour
An examination of intentions of recommending fitness centers by user members
The goal of this study was to examine what experiences members have with fitness centers that influence
their intentions for recommendation. After item generation and content validity, as well as a pilot test, a survey was
conducted among members of five different clubs (n=1750). The questionnaire included measures of service quality
attributes, accessibility, well-being in life, well-being in a club, and intentions to recommend a fitness center. Results
using a structural equation model provide evidence that only service quality attributes and well-being in a club have
positive effect on intentions of users to recommend it. Well-being in life has a negative effect on the intentions for recommendation,
while accessibility shows no predictive effect. These findings suggest implications for the management
of a club, such as the need to create a pleasant environment and to provide a personalized service directed towards the
members’ goals in order to improve well-being in a club and contribute to increase the intentions to recommend the
fitness centers to others.O objetivo
deste estudo foi examinar como as experiências de usuários de centros de atividade física interferem nas intenções em
recomendar serviços. Depois de gerar itens e validar o conteúdo, aplicou-se um pré-teste, o questionário final foi aplicado
a sócios de cinco clubes de fitness (n=1.750). O questionário incluiu atributos da qualidade do serviço, acessibilidade,
bem-estar na vida, bem-estar no clube e intenção de recomendar. O modelo de equações estruturais mostrou que apenas
os atributos da qualidade do serviço e bem-estar no clube têm um efeito positivo sobre as intenções de recomendar.
O bem-estar na vida tem um efeito negativo sobre as intenções para recomendar, enquanto que a acessibilidade não
mostra nenhum efeito preditivo. Estas conclusões sugerem a necessidade de criar um ambiente agradável nos clubes e
de oferecer um serviço personalizado para os objetivos dos sócios, a fim de melhorar o bem-estar no clube e contribuir
para a intenção de recomendar o ginásio.
Palavras-chave: intenção de recomendar, atributos da qualSin financiación0.191 SJR (2014) Q3, posición 172/231 Health (social science), 1027/1811 Medicine (miscellaneous); Q4, 112/128 Sports scienceUE
Gene Copy-Number Variation in Haploid and Diploid Strains of the Yeast Saccharomyces cerevisiae
The increasing ability to sequence and compare multiple individual genomes within a species has highlighted the fact that copy-number variation (CNV) is a substantial and underappreciated source of genetic diversity. Chromosome-scale mutations occur at rates orders of magnitude higher than base substitutions, yet our understanding of the mechanisms leading to CNVs has been lagging. We examined CNV in a region of chromosome 5 (chr5) in haploid and diploid strains of Saccharomyces cerevisiae. We optimized a CNV detection assay based on a reporter cassette containing the SFA1 and CUP1 genes that confer gene dosage-dependent tolerance to formaldehyde and copper, respectively. This optimized reporter allowed the selection of low-order gene amplification events, going from one copy to two copies in haploids and from two to three copies in diploids. In haploid strains, most events involved tandem segmental duplications mediated by nonallelic homologous recombination between flanking direct repeats, primarily Ty1 elements. In diploids, most events involved the formation of a recurrent nonreciprocal translocation between a chr5 Ty1 element and another Ty1 repeat on chr13. In addition to amplification events, a subset of clones displaying elevated resistance to formaldehyde had point mutations within the SFA1 coding sequence. These mutations were all dominant and are proposed to result in hyperactive forms of the formaldehyde dehydrogenase enzyme
Interferon-Alpha Mediates Restriction of Human Immunodeficiency Virus Type-1 Replication in Primary Human Macrophages at an Early Stage of Replication
Type I interferons (IFNα and β) are induced directly in response to viral infection, resulting in an antiviral state for the cell. In vitro studies have shown that IFNα is a potent inhibitor of viral replication; however, its role in HIV-1 infection is incompletely understood. In this study we describe the ability of IFNα to restrict HIV-1 infection in primary human macrophages in contrast to peripheral blood mononuclear cells and monocyte-derived dendritic cells. Inhibition to HIV-1 replication in cells pretreated with IFNα occurred at an early stage in the virus life cycle. Late viral events such as budding and subsequent rounds of infection were not affected by IFNα treatment. Analysis of early and late HIV-1 reverse transcripts and integrated proviral DNA confirmed an early post entry role for IFNα. First strand cDNA synthesis was slightly reduced but late and integrated products were severely depleted, suggesting that initiation or the nucleic acid intermediates of reverse transcription are targeted. The depletion of integrated provirus is disproportionally greater than that of viral cDNA synthesis suggesting the possibility of a least an additional later target. A role for either cellular protein APOBEC3G or tetherin in this IFNα mediated restriction has been excluded. Vpu, previously shown by others to rescue a viral budding restriction by tetherin, could not overcome this IFNα induced effect. Determining both the viral determinants and cellular proteins involved may lead to novel therapeutic approaches. Our results add to the understanding of HIV-1 restriction by IFNα
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