2,806 research outputs found
International Courts and the Crime of Genocide
En este trabajo realizo un análisis jurídico de los elementos constitutivos (tanto subjetivos como objetivos) del crimen de genocidio, tal y como han sido interpretados y aplicados por la jurisprudencia internacional. En concreto, se estudia la jurisprudencia de la Corte Internacional de Justicia, del Tribunal Internacional Penal para la antigua Yugoslavia y del Tribunal Internacional Penal para Ruanda sobre el crimen de genocidio
Supersymmetric Decays of the Z' Boson
The decay of the Z' boson into supersymmetric particles is studied. We
investigate how these supersymmetric modes affect the current limits from the
Tevatron and project the expected sensitivities at the LHC. Employing three
representative supersymmetric Z' models, namely, E_6, U(1)_{B-L}, and the
sequential model, we show that the current limits of the Z' mass from the
Tevatron could be reduced substantially due to the weakening of the branching
ratio into leptonic pairs. The mass reach for the E_6 Z' bosons is about
1.3-1.5 TeV at the LHC-7 (1 fb^{-1}), about 2.5 - 2.6 TeV at the LHC-10 (10
fb^{-1}), and about 4.2 - 4.3 TeV at the LHC-14 (100 fb^{-1}). A similar mass
reach for the U(1)_{B-L} Z' is also obtained. We also examine the potential of
identifying various supersymmetric decay modes of the Z' boson because it may
play a crucial role in the detailed dynamics of supersymmetry breaking.Comment: 30 pages, including 13 figures. improvements to the presentation and
references adde
Spontaneous R-Parity Violation, Flavor Symmetry and Tribimaximal Mixing
We explore the possibility of spontaneous R parity violation in the context
of flavor symmetry. Our model contains singlet matter chiral superfields which are arranged as triplet of
and as well as few additional Higgs chiral superfields which are singlet
under MSSM gauge group and belong to triplet and singlet representation under
the flavor symmetry. R parity is broken spontaneously by the vacuum
expectation values of the different sneutrino fields and hence we have
neutrino-neutralino as well as neutrino-MSSM gauge singlet higgsino mixings in
our model, in addition to the standard model neutrino- gauge singlet neutrino,
gaugino-higgsino and higgsino-higgsino mixings. Because all of these mixings we
have an extended neutral fermion mass matrix. We explore the low energy
neutrino mass matrix for our model and point out that with some specific
constraints between the sneutrino vacuum expectation values as well as the MSSM
gauge singlet Higgs vacuum expectation values, the low energy neutrino mass
matrix will lead to a tribimaximal mixing matrix. We also analyze the potential
minimization for our model and show that one can realize a higher vacuum
expectation value of the singlet
sneutrino fields even when the other sneutrino vacuum expectation values are
extremely small or even zero.Comment: 18 page
Arm-interarm gas abundance variations explored with MUSE: the role of spiral structure in the chemical enrichment of galaxies
Spiral arms are the most characteristic features of disc galaxies, easily distinguishable due to their association with ongoing star formation. However, the role of spiral structure in the chemical evolution of galaxies is unclear. Here, we explore gas-phase abundance variations between arm and interarm regions for a sample of 45 spiral galaxies using high spatial resolution VLT/MUSE integral field spectroscopy data. We report the presence of more metal-rich H II regions in the spiral arms with respect to the corresponding interarm regions for a large subsample of galaxies (45-65 per cent depending on the adopted calibrator for the abundance derivation). A small percentage of the sample is observed to display the opposite trend, i.e. more metal-poor H II regions in the spiral arms compared to that of the interarms (5-20 per cent depending on the calibrator). We investigate the dependence of the variations with three galaxy properties: the stellar mass, the presence of bars, and the flocculent/grand design appearance of spiral arms. In all cases, we observe that the arm interarm abundance differences are larger (positive) in more massive and grand-design galaxies. This is confirmed by an analogous spaxel-wise analysis, which also shows a noticeable effect of the presence of galactic bars, with barred systems presenting larger (positive) arm-interarm abundance variations than unbarred systems. The comparison of our results with new predictions from theoretical models exploring the nature of the spirals would highly impact on our knowledge on how these structures form and affect their host galaxies
Derivation and validation of a two‐variable index to predict 30‐day outcomes following heart failure hospitalization
Background
The LACE index—length of stay (L), acuity (A), Charlson co-morbidities (C), and emergent visits (E)—predicts 30-day outcomes following heart failure (HF) hospitalization but is complex to score. A simpler LE index (length of stay and emergent visits) could offer a practical advantage in point-of-care risk prediction.
Methods and results
This was a sub-study of the patient-centred care transitions in HF (PACT-HF) multicentre trial. The derivation cohort comprised patients hospitalized for HF, enrolled in the trial, and followed prospectively. External validation was performed retrospectively in a cohort of patients hospitalized for HF. We used log-binomial regression models with LACE or LE as the predictor and either 30-day composite all-cause readmission or death or 30-day all-cause readmission as the outcomes, adjusting only for post-discharge services. There were 1985 patients (mean [SD] age 78.1 [12.1] years) in the derivation cohort and 378 (mean [SD] age 73.1 [13.2] years) in the validation cohort. Increments in the LACE and LE indices were associated with 17% (RR 1.17; 95% CI 1.12, 1.21; C-statistic 0.64) and 21% (RR 1.21; 95% CI 1.15, 1.26; C-statistic 0.63) increases, respectively, in 30-day composite all-cause readmission or death; and 16% (RR 1.16; 95% CI 1.11, 1.20; C-statistic 0.64) and 18% (RR 1.18; 95% CI 1.13, 1.24; C-statistic 0.62) increases, respectively, in 30-day all-cause readmission. The LE index provided better risk discrimination for the 30-day outcomes than did the LACE index in the external validation cohort.
Conclusions
The LE index predicts 30-day outcomes following HF hospitalization with similar or better performance than the more complex LACE index
Goldstone Bosons in Effective Theories with Spontaneously Broken Flavour Symmetry
The Flavour Symmetry of the Standard Model (SM) gauge sector is broken by the
fermion Yukawa couplings. Promoting the Yukawa matrices to scalar spurion
fields, one can break the flavour symmetry spontaneously by giving appropriate
vacuum expectation values (VEVs) to the spurion fields, and one encounters
Goldstone modes for every broken flavour symmetry generator. In this paper, we
point out various aspects related to the possible dynamical interpretation of
the Goldstone bosons: (i) In an effective-theory framework with local flavour
symmetry, the Goldstone fields represent the longitudinal modes for massive
gauge bosons. The spectrum of the latter follows the sequence of
flavour-symmetry breaking related to the hierarchies in Yukawa couplings and
flavour mixing angles. (ii) Gauge anomalies can be consistently treated by
adding higher-dimensional operators. (iii) Leaving the U(1) factors of the
flavour symmetry group as global symmetries, the respective Goldstone modes
behave as axions which can be used to resolve the strong CP problem by a
modified Peccei-Quinn mechanism. (iv) The dynamical picture of flavour symmetry
breaking implies new sources of flavour-changing neutral currents, which arise
from integrating out heavy scalar spurion fields and heavy gauge bosons. The
coefficients of the effective operators follow the minimal-flavour violation
principle.Comment: 27 pages, abstract and introduction extended, more detailed
discussion of heavy gauge boson spectrum and auxiliary heavy fermions,
outline restructured. Matches version to be published in JHE
Anaerobic Carbon Monoxide Dehydrogenase Diversity in the Homoacetogenic Hindgut Microbial Communities of Lower Termites and the Wood Roach
Anaerobic carbon monoxide dehydrogenase (CODH) is a key enzyme in the Wood-Ljungdahl (acetyl-CoA) pathway for acetogenesis performed by homoacetogenic bacteria. Acetate generated by gut bacteria via the acetyl-CoA pathway provides considerable nutrition to wood-feeding dictyopteran insects making CODH important to the obligate mutualism occurring between termites and their hindgut microbiota. To investigate CODH diversity in insect gut communities, we developed the first degenerate primers designed to amplify cooS genes, which encode the catalytic (β) subunit of anaerobic CODH enzyme complexes. These primers target over 68 million combinations of potential forward and reverse cooS primer-binding sequences. We used the primers to identify cooS genes in bacterial isolates from the hindgut of a phylogenetically lower termite and to sample cooS diversity present in a variety of insect hindgut microbial communities including those of three phylogenetically-lower termites, Zootermopsis nevadensis, Reticulitermes hesperus, and Incisitermes minor, a wood-feeding cockroach, Cryptocercus punctulatus, and an omnivorous cockroach, Periplaneta americana. In total, we sequenced and analyzed 151 different cooS genes. These genes encode proteins that group within one of three highly divergent CODH phylogenetic clades. Each insect gut community contained CODH variants from all three of these clades. The patterns of CODH diversity in these communities likely reflect differences in enzyme or physiological function, and suggest that a diversity of microbial species participate in homoacetogenesis in these communities
A molecular insight into algal-oomycete warfare : cDNA analysis of Ectocarpus siliculosus infected with the basal oomycete Eurychasma dicksonii
Peer reviewedPublisher PD
Reliable transfer of transcriptional gene regulatory networks between taxonomically related organisms
Baumbach J, Rahmann S, Tauch A. Reliable transfer of transcriptional gene regulatory networks between taxonomically related organisms. BMC Systems Biology. 2009;3(1):8.Background: Transcriptional regulation of gene activity is essential for any living organism. Transcription factors therefore recognize specific binding sites within the DNA to regulate the expression of particular target genes. The genome-scale reconstruction of the emerging regulatory networks is important for biotechnology and human medicine but cost-intensive, time-consuming, and impossible to perform for any species separately. By using bioinformatics methods one can partially transfer networks from well-studied model organisms to closely related species. However, the prediction quality is limited by the low level of evolutionary conservation of the transcription factor binding sites, even within organisms of the same genus. Results: Here we present an integrated bioinformatics workflow that assures the reliability of transferred gene regulatory networks. Our approach combines three methods that can be applied on a large-scale: re-assessment of annotated binding sites, subsequent binding site prediction, and homology detection. A gene regulatory interaction is considered to be conserved if (1) the transcription factor, (2) the adjusted binding site, and (3) the target gene are conserved. The power of the approach is demonstrated by transferring gene regulations from the model organism Corynebacterium glutamicum to the human pathogens C. diphtheriae, C. jeikeium, and the biotechnologically relevant C. efficiens. For these three organisms we identified reliable transcriptional regulations for similar to 40% of the common transcription factors, compared to similar to 5% for which knowledge was available before. Conclusion: Our results suggest that trustworthy genome-scale transfer of gene regulatory networks between organisms is feasible in general but still limited by the level of evolutionary conservation
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