268 research outputs found
Eukaryotic HMGB proteins as replacements for HU in E. coli repression loop formation
DNA looping is important for gene repression and activation in Escherichia coli and is necessary for some kinds of gene regulation and recombination in eukaryotes. We are interested in sequence-nonspecific architectural DNA-binding proteins that alter the apparent flexibility of DNA by producing transient bends or kinks in DNA. The bacterial heat unstable (HU) and eukaryotic high-mobility group B (HMGB) proteins fall into this category. We have exploited a sensitive genetic assay of DNA looping in living E. coli cells to explore the extent to which HMGB proteins and derivatives can complement a DNA looping defect in E. coli lacking HU protein. Here, we show that derivatives of the yeast HMGB protein Nhp6A rescue DNA looping in E. coli lacking HU, in some cases facilitating looping to a greater extent than is observed in E. coli expressing normal levels of HU protein. Nhp6A-induced changes in the DNA length-dependence of repression efficiency suggest that Nhp6A alters DNA twist in vivo. In contrast, human HMGB2-box A derivatives did not rescue looping
A Long Baseline Neutrino Oscillation Experiment Using J-PARC Neutrino Beam and Hyper-Kamiokande
Document submitted to 18th J-PARC PAC meeting in May 2014. 50 pages, 41 figuresDocument submitted to 18th J-PARC PAC meeting in May 2014. 50 pages, 41 figuresDocument submitted to 18th J-PARC PAC meeting in May 2014. 50 pages, 41 figuresHyper-Kamiokande will be a next generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of Hyper-Kamiokande is the study of asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this document, the physics potential of a long baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from the J-PARC proton synchrotron is presented. The analysis has been updated from the previous Letter of Intent [K. Abe et al., arXiv:1109.3262 [hep-ex]], based on the experience gained from the ongoing T2K experiment. With a total exposure of 7.5 MW 10 sec integrated proton beam power (corresponding to protons on target with a 30 GeV proton beam) to a -degree off-axis neutrino beam produced by the J-PARC proton synchrotron, it is expected that the phase can be determined to better than 19 degrees for all possible values of , and violation can be established with a statistical significance of more than () for () of the parameter space
Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF
The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at
the Fermilab Long-Baseline Neutrino Facility (LBNF) is described
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
Anxiety as a cause of attachment avoidance in women with Turner Syndrome
Working models of attachment are internal depictions of self relative to others and have been described in terms of two dimensions: (1) attachment avoidance and (2) attachment anxiety. An exploratory qualitative study was carried out to build understandings about women with Turner Syndrome (TS) and the psychosocial impact their infertility has upon salient relationships. In one-to-one semi-structured interviews, five women with TS were asked: How do you perceive your womanhood and infertility status has affected your relationships with: (1) the opposite sex, (2) siblings and (3) peers? In opposite-sex relationships, infertility status was found to arouse fear of ending up alone and anxiety over engaging in romantic relationships. In sibling relationships, jealousy was expressed in relation to disparity with sister(s) more natural maturation to womanhood, and, within peer relationships, consequences from divulging infertility status created attachment avoidance with friends. Further investigation in this area is merited
Neurodevelopment Genes in Lampreys Reveal Trends for Forebrain Evolution in Craniates
The forebrain is the brain region which has undergone the most dramatic changes through vertebrate evolution. Analyses conducted in lampreys are essential to gain insight into the broad ancestral characteristics of the forebrain at the dawn of vertebrates, and to understand the molecular basis for the diversifications that have taken place in cyclostomes and gnathostomes following their splitting. Here, we report the embryonic expression patterns of 43 lamprey genes, coding for transcription factors or signaling molecules known to be involved in cell proliferation, stemcellness, neurogenesis, patterning and regionalization in the developing forebrain. Systematic expression patterns comparisons with model organisms highlight conservations likely to reflect shared features present in the vertebrate ancestors. They also point to changes in signaling systems âpathways which control the growth and patterning of the neuroepithelium-, which may have been crucial in the evolution of forebrain anatomy at the origin of vertebrates
Cost-Effectiveness of HIV Treatment as Prevention in Serodiscordant Couples
The cost-effectiveness of early antiretroviral therapy (ART) in persons infected with human immunodeficiency virus (HIV) in serodiscordant couples is not known. Using a computer simulation of the progression of HIV infection and data from the HIV Prevention Trials Network 052 study, we projected the cost-effectiveness of early ART for such persons
Evolution of retinoic acid receptors in chordates: insights from three lamprey species, Lampetra fluviatilis, Petromyzon marinus, and Lethenteron japonicum
Folk psychological and neurocognitive ontologies
It is becoming increasingly clear that our folk psychological ontology of the mental is unlikely to map neatly on to the functional organisation of the brain, leading to the development of novel âcognitive ontologiesâ that aim to better describe this organisation. While the debate over which of these ontologies to adopt is still ongoing, we ought to think carefully about what the consequences for folk psychology might be. One option would be to endorse a new form of eliminative materialism, replacing the old folk psychological ontology with a novel neurocognitive ontology. This approach assumes a literalist attitude towards folk psychology, where the folk psychological and neurocognitive ontologies represent competing and incompatible ways of categorising the mental. According to an alternative approach, folk psychology aims to describe coarse-grained behaviour rather than fine-grained mechanisms, and the two kinds of ontology are better thought of as having different aims and purposes. In this chapter I will argue that the latter (coarse-grained) approach is a better way to make sense of everyday folk psychological practice, and also offers a more constructive way to understand the relationship between folk psychological and neurocognitive ontologies. The folk psychological ontology of the mental might not be appropriate for describing the functional organisation of the brain, but rather than eliminating or revising it, we should instead recognise that it has a very different aim and purpose than neurocognitive ontologies
Physics potential of a long-baseline neutrino oscillation experiment using a J-PARC neutrino beam and Hyper-Kamiokande
39 pages, 26 figures, submitted to PTE
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