1,335 research outputs found
On finite monoids of cellular automata.
For any group G and set A, a cellular automaton over G and A is a transformation Ï:AGâAGÏ:AGâAG defined via a finite neighbourhood SâGSâG (called a memory set of ÏÏ) and a local function ÎŒ:ASâAÎŒ:ASâA. In this paper, we assume that G and A are both finite and study various algebraic properties of the finite monoid CA(G,A)CA(G,A) consisting of all cellular automata over G and A. Let ICA(G;A)ICA(G;A) be the group of invertible cellular automata over G and A. In the first part, using information on the conjugacy classes of subgroups of G, we give a detailed description of the structure of ICA(G;A)ICA(G;A) in terms of direct and wreath products. In the second part, we study generating sets of CA(G;A)CA(G;A). In particular, we prove that CA(G,A)CA(G,A) cannot be generated by cellular automata with small memory set, and, when G is finite abelian, we determine the minimal size of a set VâCA(G;A)VâCA(G;A) such that CA(G;A)=âšICA(G;A)âȘVâ©CA(G;A)=âšICA(G;A)âȘVâ©
Reduced transcription of TCOF1 in adult cells of Treacher Collins syndrome patients
<p>Abstract</p> <p>Background</p> <p>Treacher Collins syndrome (TCS) is an autosomal dominant craniofacial disorder caused by frameshift deletions or duplications in the <it>TCOF1 </it>gene. These mutations cause premature termination codons, which are predicted to lead to mRNA degradation by nonsense mediated mRNA decay (NMD). Haploinsufficiency of the gene product (treacle) during embryonic development is the proposed molecular mechanism underlying TCS. However, it is still unknown if <it>TCOF1 </it>expression levels are decreased in post-embryonic human cells.</p> <p>Methods</p> <p>We have estimated <it>TCOF1 </it>transcript levels through real time PCR in mRNA obtained from leucocytes and mesenchymal cells of TCS patients (n = 23) and controls (n = 18). Mutational screening and analysis of NMD were performed by direct sequencing of gDNA and cDNA, respectively.</p> <p>Results</p> <p>All the 23 patients had typical clinical features of the syndrome and pathogenic mutations were detected in 19 of them. We demonstrated that the expression level of <it>TCOF1 </it>is 18-31% lower in patients than in controls (<it>p < 0.05</it>), even if we exclude the patients in whom we did not detect the pathogenic mutation. We also observed that the mutant allele is usually less abundant than the wild type one in mesenchymal cells.</p> <p>Conclusions</p> <p>This is the first study to report decreased expression levels of <it>TCOF1 </it>in TCS adult human cells, but it is still unknown if this finding is associated to any phenotype in adulthood. In addition, as we demonstrated that alleles harboring the pathogenic mutations have lower expression, we herein corroborate the current hypothesis of NMD of the mutant transcript as the explanation for diminished levels of <it>TCOF1 </it>expression. Further, considering that <it>TCOF1 </it>deficiency in adult cells could be associated to pathologic clinical findings, it will be important to verify if TCS patients have an impairment in adult stem cell properties, as this can reduce the efficiency of plastic surgery results during rehabilitation of these patients.</p
Extremely high He isotope ratios in MORB-source mantle from the proto-Iceland plume
The high <sup>3</sup>He/<sup>4</sup>He ratio of volcanic rocks thought to be derived from mantle plumes is taken as evidence for the existence of a mantle reservoir that has remained largely undegassed since the Earth's accretion. The helium isotope composition of this reservoir places constraints on the origin of volatiles within the Earth and on the evolution and structure of the Earth's mantle. Here we show that olivine phenocrysts in picritic basalts presumably derived from the proto-Iceland plume at Baffin Island, Canada, have the highest magmatic <sup>3</sup>He/<sup>4</sup>He ratios yet recorded. A strong correlation between <sup>3</sup>He/<sup>4</sup>He and <sup>87</sup>Sr/<sup>86</sup>Sr, <sup>143</sup>Nd/<sup>144</sup>Nd and trace element ratios demonstrate that the <sup>3</sup>He-rich end-member is present in basalts that are derived from large-volume melts of depleted upper-mantle rocks. This reservoir is consistent with the recharging of depleted upper-mantle rocks by small volumes of primordial volatile-rich lower-mantle material at a thermal boundary layer between convectively isolated reservoirs. The highest <sup>3</sup>He/<sup>4</sup>He basalts from Hawaii and Iceland plot on the observed mixing trend. This indicates that a <sup>3</sup>He-recharged depleted mantle (HRDM) reservoir may be the principal source of high <sup>3</sup>He/<sup>4</sup>He in mantle plumes, and may explain why the helium concentration of the 'plume' component in ocean island basalts is lower than that predicted for a two-layer, steady-state model of mantle structure
W+W-, WZ and ZZ production in the POWHEG BOX
We present an implementation of the vector boson pair production processes
ZZ, W+W- and W Z within the POWHEG framework, which is a method that allows the
interfacing of NLO calculations to shower Monte Carlo programs. The
implementation is built within the POWHEG BOX package. The Z/\gamma^*
interference, as well as singly resonant contributions, are properly included.
We also considered interference terms arising from identical leptons in the
final state. As a result, all contributions leading to the desired four-lepton
system have been included in the calculation, with the sole exception of the
interference between ZZ and W+W- in the production of a pair of same-flavour,
oppositely charged fermions and a pair of neutrinos, which we show to be fully
negligible. Anomalous trilinear couplings can be also set in the program, and
we give some examples of their effect at the LHC. We have made the relevant
code available at the POWHEG BOX web site.Comment: 20 pages, 9 figures, 2 tables. Minor corrections and updated
references in revised versio
NLO Higgs boson production plus one and two jets using the POWHEG BOX, MadGraph4 and MCFM
We present a next-to-leading order calculation of Higgs boson production plus
one and two jets via gluon fusion interfaced to shower Monte Carlo programs,
implemented according to the POWHEG method. For this implementation we have
used a new interface of the POWHEG BOX with MadGraph4, that generates the codes
for generic Born and real processes automatically. The virtual corrections have
been taken from the MCFM code. We carry out a simple phenomenological study of
our generators, comparing them among each other and with fixed next-to-leading
order results.Comment: 27 pages, 21 figure
Sparticle Spectrum of Large Volume Compactification
We examine the large volume compactification of Type IIB string theory or its
F theory limit and the associated supersymmetry breakdown and soft terms. It is
crucial to incorporate the loop-induced moduli mixing, originating from
radiative corrections to the Kahler potential. We show that in the presence of
moduli mixing, soft scalar masses generically receive a D-term contribution of
the order of the gravitino mass m_{3/2} when the visible sector cycle is
stabilized by the D-term potential of an anomalous U(1) gauge symmetry, while
the moduli-mediated gaugino masses and A-parameters tend to be of the order of
m_{3/2}/8pi^2. It is noticed also that a too large moduli mixing can
destabilize the large volume solution by making it a saddle point.Comment: 29 page
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In-street wind direction variability in the vicinity of a busy intersection in central London
We present results from fast-response wind measurements within and above a busy intersection between two street canyons (Marylebone Road and Gloucester Place) in Westminster, London taken as part of the DAPPLE (Dispersion of Air Pollution and Penetration into the Local Environment; www.dapple.org.uk) 2007 field campaign. The data reported here were collected using ultrasonic anemometers on the roof-top of a building adjacent to the intersection and at two heights on a pair of lamp-posts on opposite sides of the intersection. Site characteristics, data analysis and the variation of intersection flow with the above-roof wind direction (Ξref) are discussed. Evidence of both flow channelling and recirculation was identified within the canyon, only a few metres from the intersection for along-street and across-street roof-top winds respectively. Results also indicate that for oblique rooftop flows, the intersection flow is a complex combination of bifurcated channelled flows, recirculation and corner vortices. Asymmetries in local building geometry around the intersection and small changes in the background wind direction (changes in 15-min mean Ξref of 5â10 degrees) were also observed to have profound influences on the behaviour of intersection flow patterns. Consequently, short time-scale variability in the background flow direction can lead to highly scattered in-street mean flow angles masking the true multi-modal features of the flow and thus further complicating modelling challenges
Enrichment analysis of Alu elements with different spatial chromatin proximity in the human genome
Transposable elements (TEs) have no longer been totally considered as âjunk DNAâ for quite a time since the continual discoveries of their multifunctional roles in eukaryote genomes. As one of the most important and abundant TEs that still active in human genome, Alu, a SINE family, has demonstrated its indispensable regulatory functions at sequence level, but its spatial roles are still unclear. Technologies based on 3C(chromosomeconformation capture) have revealed the mysterious three-dimensional structure of chromatin, and make it possible to study the distal chromatin interaction in the genome. To find the role TE
playing in distal regulation in human genome, we compiled the new released Hi-C data, TE annotation, histone marker annotations, and the genome-wide methylation data to operate correlation analysis, and found that the density of Alu elements showed a strong positive correlation with the level of chromatin interactions (hESC: r=0.9, P<2.2Ă1016; IMR90 fibroblasts: r = 0.94, P < 2.2 Ă 1016) and also have a significant positive correlation withsomeremote functional DNA elements like enhancers and promoters (Enhancer: hESC: r=0.997, P=2.3Ă10â4; IMR90: r=0.934, P=2Ă10â2; Promoter: hESC: r = 0.995, P = 3.8 Ă 10â4; IMR90: r = 0.996, P = 3.2 Ă 10â4). Further investigation involving GC content and methylation status showed the GC content of Alu covered sequences shared a similar pattern with that of the overall sequence, suggesting that Alu elements also function as the GC nucleotide and CpG site provider. In all, our results suggest that the Alu elements may act as an alternative parameter to evaluate the Hi-C data, which is confirmed by the correlation analysis of Alu elements and histone markers. Moreover, the GC-rich Alu sequence can bring high GC content and methylation flexibility to the regions with more distal chromatin contact, regulating the transcription of tissue-specific genes
Evaluative and discriminative properties of the Portuguese MacNew Heart Disease Healthârelated Quality of Life Questionnaire.
Qual Life Res. 2005 Dec;14(10):2335-41.
Evaluative and discriminative properties of the Portuguese MacNew Heart Disease Health-related Quality of Life Questionnaire.
Leal A, Paiva C, Höfer S, Amado J, Gomes L, Oldridge N.
Cardiac Rehabilitation Unit, Hospital Sto AntĂłnio Porto, Largo Prof Abel Salazar 400, Portugal. [email protected]
Abstract
The aim of this study was to validate the Portuguese version of the self-administered MacNew Heart Disease Health-related Quality of Life (MacNew) questionnaire in patients after diagnosis of acute coronary syndrome. The MacNew, with a Global score and physical, emotional and social subscales, the Short Form SF-36 (SF-36) and the Hospital Anxiety and Depression Scale (HADS) were completed at baseline by 150 patients and again by 48 clinically stable patients 2-3 weeks later. A cohort of 50 different patients completed the same questionnaires before and after a cardiac rehabilitation program in order to examine responsiveness. Acceptance of the MacNew by the patients was good and the three factor model was substantiated and explained 52.2% of the variance. Internal consistency, intra-class-correlation, and test-retest reliability each exceeded 0.72. The predicted construct validity hypotheses were partially confirmed. The discriminative validity of the MacNew was confirmed with significantly higher MacNew scores for patients with normal left ventricular function, with improved health status, and who were not anxious or depressed. Even though MacNew scores improved significantly following cardiac rehabilitation, the evaluative validity of the MacNew was less robust with small responsiveness statistics. The Portuguese version of the MacNew HRQL questionnaire appears to be a reliable, valid, and moderately responsive instrument to evaluate health-related quality of life after diagnosis of acute coronary syndrome.
PMID: 16328913 [PubMed - indexed for MEDLINE
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