695 research outputs found
Accurate structure factors from pseudopotential methods
Highly accurate experimental structure factors of silicon are available in
the literature, and these provide the ideal test for any \emph{ab initio}
method for the construction of the all-electron charge density. In a recent
paper [J. R. Trail and D. M. Bird, Phys. Rev. B {\bf 60}, 7863 (1999)] a method
has been developed for obtaining an accurate all-electron charge density from a
first principles pseudopotential calculation by reconstructing the core region
of an atom of choice. Here this method is applied to bulk silicon, and
structure factors are derived and compared with experimental and Full-potential
Linear Augmented Plane Wave results (FLAPW). We also compare with the result of
assuming the core region is spherically symmetric, and with the result of
constructing a charge density from the pseudo-valence density + frozen core
electrons. Neither of these approximations provide accurate charge densities.
The aspherical reconstruction is found to be as accurate as FLAPW results, and
reproduces the residual error between the FLAPW and experimental results.Comment: 6 Pages, 3 figure
Ab initio study of the volume dependence of dynamical and thermodynamical properties of silicon
Motivated by the negative thermal expansion observed for silicon between 20 K
and 120 K, we present first an ab initio study of the volume dependence of
interatomic force constants, phonon frequencies of TA(X) and TA(L) modes, and
of the associated mode Gruneisen parameters. The influence of successive
nearest neighbors shells is analysed. Analytical formulas, taking into account
interactions up to second nearest neighbors, are developped for phonon
frequencies of TA(X) and TA(L) modes and the corresponding mode Gruneisen
parameters. We also analyze the volume and pressure dependence of various
thermodynamic properties (specific heat, bulk modulus, thermal expansion), and
point out the effect of the negative mode Gruneisen parameters of the acoustic
branches on these properties. Finally, we present the evolution of the mean
square atomic displacement and of the atomic temperature factor with the
temperature for different volumes, for which the anomalous effects are even
greater.Comment: 24 pages, Revtex 3.0, 11 figures, accepted for publication in Phys.
Rev.
Monitoring changes in thioredoxin and over-oxidised peroxiredoxin in response to exercise in humans
This paper is closed access.Introduction. Peroxiredoxin (PRDX) and thioredoxin (TRX) are antioxidant proteins that control cellular signalling and redox balance, although their response to exercise is unknown. This study aimed to assess key aspects of the PRDX–TRX redox cycle in response to three different modes of exercise. Methods. Healthy males (n = 10, mean ± SD: 22 ± 3 yrs) undertook three exercise trials on separate days: two steady-state cycling trials at moderate (60% O2MAX; 27 min, MOD) and high (80% O2MAX; 20 min, HIGH) intensities, and a low-volume high-intensity interval training trial (10 × 1 min 90% O2MAX, LV-HIIT). Peripheral blood mononuclear cells were assessed for TRX-1 and over-oxidised PRDX (isoforms I–IV) protein expression before, during, and 30 min following exercise (post + 30). The activities of TRX reductase (TRX-R) and the nuclear factor kappa B (NF-κB) p65 subunit were also assessed. Results. TRX-1 increased during exercise in all trials (MOD, + 84.5%; HIGH, + 64.1%; LV-HIIT, + 205.7%; p < 05), whereas over-oxidised PRDX increased during HIGH only (MOD, − 28.7%; HIGH, + 202.9%; LV-HIIT, − 22.7%; p < .05). TRX-R and NF-κB p65 activity increased during exercise in all trials, with the greatest response in TRX-R activity seen in HIGH (p < 0.05). Discussion. All trials stimulated a transient increase in TRX-1 protein expression during exercise. Only HIGH induced a transient over-oxidation of PRDX, alongside the greatest change in TRX-R activity. Future studies are needed to clarify the significance of heightened peroxide exposure during continuous high-intensity exercise and the mechanisms of PRDX-regulatory control
Biblical Theology of Life in the New Testament
This publication deals with A Biblical Theology of Life based on the New Testament. It forms the second of a two volume publication on A Biblical Theology of Life. These two volumes trace the concept of life throughout Protestant canon, working with the final form of the biblical books in Hebrew (vol. 5) and Greek (vol. 6) Scripture. This is done by providing the reader with a book-by-book overview of this concept. This book concludes with a final chapter synthesising the findings of the respective investigations of the Old and New Testament corpora in order to provide a summative theological perspective of the development of the concept through Scripture. It is clear that life forms a central and continuous theme throughout the Biblical text. The theme begins with the living God that creates life, but is shortly followed by death that threatens life. Despite this threat, God sustains life and awakens life from death. The text concludes with the consummation depicting eternal life in the new heaven and earth. The biblical theological approach that has been taken entails a thematic approach as it investigates the concept of life, with contextual foci on what individual books of Scripture teach about life, joined diachronically with an investigation of the progressive use of the concept of life in Scripture, while providing a theology of Scripture as a whole investigating the concept of life in all sixty-six books of the Protestant canon
Biblical Theology of Life in the New Testament
This publication deals with A Biblical Theology of Life based on the New Testament. It forms the second of a two volume publication on A Biblical Theology of Life. These two volumes trace the concept of life throughout Protestant canon, working with the final form of the biblical books in Hebrew (vol. 5) and Greek (vol. 6) Scripture. This is done by providing the reader with a book-by-book overview of this concept. This book concludes with a final chapter synthesising the findings of the respective investigations of the Old and New Testament corpora in order to provide a summative theological perspective of the development of the concept through Scripture. It is clear that life forms a central and continuous theme throughout the Biblical text. The theme begins with the living God that creates life, but is shortly followed by death that threatens life. Despite this threat, God sustains life and awakens life from death. The text concludes with the consummation depicting eternal life in the new heaven and earth. The biblical theological approach that has been taken entails a thematic approach as it investigates the concept of life, with contextual foci on what individual books of Scripture teach about life, joined diachronically with an investigation of the progressive use of the concept of life in Scripture, while providing a theology of Scripture as a whole investigating the concept of life in all sixty-six books of the Protestant canon
Rudimentary signs of immunosenescence in <em>Cytomegalovirus</em>-seropositive healthy young adults
Ageing is associated with a decline in immune competence termed immunosenescence. In the elderly, this process results in an accumulation of differentiated ‘effector’ phenotype memory T cells, predominantly driven by Cytomegalovirus (CMV) infection. Here, we asked whether CMV also drives immunity towards a senescent profile in healthy young adults. One hundred and fifty-eight individuals (mean ± SD; age 21 ± 3 years, body mass index 22.7 ± 2.7 kg m2) were assessed for CMV serostatus, the numbers/proportions of CD4+ and CD8+ late differentiated/effector memory cells (i.e. CD27−CD28−/CD45RA+), plasma interleukin-6 (IL-6) and antibody responses to an in vivo antigen challenge (half-dose influenza vaccine). Thirty percent (48/158) of participants were CMV+. A higher lymphocyte and CD8+ count (both p < 0.01) and a lower CD4/CD8 ratio (p < 0.03) were observed in CMV+ people. Eight percent (4/58) of CMV+ individuals exhibited a CD4/CD8 ratio <1.0, whereas no CMV− donor showed an inverted ratio (p < 0.001). The numbers of CD4+ and CD8+CD27−CD28−/CD45RA+ cells were ~ fourfold higher in CMV+ people (p < 0.001). Plasma IL-6 was higher in CMV+ donors (p < 0.05) and showed a positive association with the numbers of CD8+CD28− cells (p < 0.03). Finally, there was a significant negative correlation between vaccine-induced antibody responses to the A/Brisbane influenza strain and CMV-specific immunoglobulin G titres (p < 0.05). This reduced vaccination response was associated with greater numbers of total CD8+ and CD4+ and CD8+CD27−CD28−/CD45RA+ cells (p < 0.05). This study observed marked changes in the immune profile of young adults infected with CMV, suggesting that this virus may underlie rudimentary aspects of immunosenescence even in a chronologically young population
De novo unbalanced translocations have a complex history/aetiology
We investigated 52 cases of de novo unbalanced translocations, consisting in a terminally deleted or inverted-duplicated deleted (inv-dup del) 46th chromosome to which the distal portion of another chromosome or its opposite end was transposed. Array CGH, whole-genome sequencing, qPCR, FISH, and trio genotyping were applied. A biparental origin of the deletion and duplication was detected in 6 cases, whereas in 46, both imbalances have the same parental origin. Moreover, the duplicated region was of maternal origin in more than half of the cases, with 25% of them showing two maternal and one paternal haplotype. In all these cases, maternal age was increased. These findings indicate that the primary driver for the occurrence of the de novo unbalanced translocations is a maternal meiotic non-disjunction, followed by partial trisomy rescue of the supernumerary chromosome present in the trisomic zygote. In contrast, asymmetric breakage of a dicentric chromosome, originated either at the meiosis or postzygotically, in which the two resulting chromosomes, one being deleted and the other one inv-dup del, are repaired by telomere capture, appears at the basis of all inv-dup del translocations. Notably, this mechanism also fits with the origin of some simple translocations in which the duplicated region was of paternal origin. In all cases, the signature at the translocation junctions was that of non-homologous end joining (NHEJ) rather than non-allelic homologous recombination (NAHR). Our data imply that there is no risk of recurrence in the following pregnancies for any of the de novo unbalanced translocations we discuss here
Expressive free speech, the state, and the public sphere: A Bakhtinian–Deleuzian analysis of ‘public address’ at Hyde Park
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2008 Taylor & Francis.In this paper I explore how struggles around free speech between social movements and the state are often underpinned by a deeper struggle around expressive images of what counts as either ‘decent’ or ‘indecent’ discussion. These points are developed by exploring what is arguably the most famous populist place for free speech in Britain, namely Hyde Park. In 1872 the state introduced the Parks Regulation Act in order to regulate, amongst other things, populist uses of free speech at Hyde Park. However, although the 1872 Act designated a site in Hyde Park for public meetings, it did not mention ‘free speech’. Rather, the 1872 Act legally enforced the liberty to make a ‘public address’ and this was implicitly contrasted by the state of an expressive image of ‘indecent’ speakers exercising their ‘right’ of free speech at Hyde Park. Once constructed, the humiliating image of ‘indecent’ free speech could then be used by the state to regulate actual utterances of public speakers at Hyde Park. But the paper shows how in the years immediately following 1872 a battle was fought out in Hyde Park over the expressive image of public address between the state and regulars using Hyde Park as a public sphere to exercise free speech. For its part the state had to engage in meaningful deliberative forms of discussion within its own regulatory framework and with the public sphere at Hyde Park in order to maintain the legal form, content and expression of the 1872 Act. To draw out the implications of these points I employ some of the theoretical ideas of the Bakhtin Circle and Gilles Deleuze. Each set of thinkers in their own way make valuable contributions for understanding the relationship between the state, public sphere and expressive images
Randomized Controlled Caregiver Mediated Joint Engagement Intervention for Toddlers with Autism
This study aimed to determine if a joint attention intervention would result in greater joint engagement between caregivers and toddlers with autism. The intervention consisted of 24 caregiver-mediated sessions with follow-up 1 year later. Compared to caregivers and toddlers randomized to the waitlist control group the immediate treatment (IT) group made significant improvements in targeted areas of joint engagement. The IT group demonstrated significant improvements with medium to large effect sizes in their responsiveness to joint attention and their diversity of functional play acts after the intervention with maintenance of these skills 1 year post-intervention. These are among the first randomized controlled data to suggest that short-term parent-mediated interventions can have important effects on core impairments in toddlers with autism. Clinical Trials #: NCT00065910
Beta-defensin genomic copy number is not a modifier locus for cystic fibrosis
Human beta-defensin 2 (DEFB4, also known as DEFB2 or hBD-2) is a salt-sensitive antimicrobial protein that is expressed in lung epithelia. Previous work has shown that it is encoded in a cluster of beta-defensin genes at 8p23.1, which varies in copy number between 2 and 12 in different individuals. We determined the copy number of this locus in 355 patients with cystic fibrosis (CF), and tested for correlation between beta-defensin cluster genomic copy number and lung disease associated with CF. No significant association was found
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