12 resultados para Almost Kneser Subgroup

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Engelmann believes in two general strong beliefs. On one side, Engelmann believes in probabilistic skepticism. That the existence has its maximum probability or there is no existence at all is not possible. The other probabilities of existence are always possible. On the other hand, instead of elements that constitute a beginning arrived at by an unknown division, the Gestalt theory begins with wholes or Gestalten. These Gestalten can be divided in parts but each part can be only a part of his specific Gestalt. The majority of probabilistic skeptics and the majority of Gestalt theory followers do not believe they can be together accepted. On the contrary Engelmann is a member of a small group that both beliefs occur simultaneously. Bibace`s questions were each answered by Engelmann. In some questions Engelmann harmonize with Bibace, in others they disagree.

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Almost fifty years after the discovery of the peroxyoxalate reaction by E. A. Chandross in the early nineteen sixties, this review article intends to give a general overview on mechanistic aspects of this system and to describe the principles of its analytical application. After a short general introduction on the principles of chemiluminescence and the history of peroxyoxalate discovery, mechanistic aspects of high-energy intermediate formation, its structure and its reaction with an activator in the peroxyoxalate system are discussed. Finally, analytical applications of peroxyoxalate chemiluminescence are exemplified using representative recent examples, including oxalic acid detection in biological samples.

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We show that if p is a selective ultrafilter, then for each cardinal alpha <= omega(1), there exists a topological group G such that G(beta) is almost p-compact (in particular, countably compact), for beta < alpha, but G(alpha) is not countably compact. If in addition, we assume Martin's Axiom, then the result above holds for every alpha < c. (C) 2012 Elsevier By. All rights reserved.

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Early diagenetic chert, infrequently exploited in Phanerozoic micropaleontology, was examined for organic-walled microfossils in petrographic thin sections of silicified dolostones from diverse levels and localities of the Assistencia Formation (Permian, Parana Basin) in the state of Sao Paulo, Brazil. In contrast to previous palynological studies of this formation, the use of thin sections allowed direct observation in three dimensions of common palynomorphs, as well as benthic microbial mats preserved in situ in various stages of their life cycles and degradation. As in palynological residues from the more wellknown shale of this formation, the chert contains wind-dispersed pollen grains and phytoclasts derived from terrestrial sources and planktonic cryptarchs (unornamented coccoidal unicellular or colonial palynomorphs). However, only in the chert is it possible to see much more delicate microfossils, such as abundant cyanobacteria of the in situ benthic microbiota as well as chlorophycean microalgae of the microphytoplankton. Post-depositional processes affecting the formation have destroyed all but the most resistant organic remains in the other lithologies, such that only rare, degraded pollen grains are seen in the unsilicified dolostone of the formation, and in the shale the vast majority of microfossils have been compacted to flattened disks. On the other hand, early silicification not only preserved organic remains at an incipient stage of decomposition but also impeded significant further degradation due to compaction, recrystallization, and oxidation. Thus, the petrographic study of such chert can complement traditional palynological investigations in Phanerozoic rocks by furnishing hitherto unavailable information, especially with regard to benthic organic microfossils and fragile organic-walled phytoplankton normally absent from organic residues. (C) 2011 Elsevier Ltd. All rights reserved.

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Medulloblastoma, the most common malignant paediatric brain tumour, is currently treated with nonspecific cytotoxic therapies including surgery, whole-brain radiation, and aggressive chemotherapy. As medulloblastoma exhibits marked intertumoural heterogeneity, with at least four distinct molecular variants, previous attempts to identify targets for therapy have been underpowered because of small samples sizes. Here we report somatic copy number aberrations (SCNAs) in 1,087 unique medulloblastomas. SCNAs are common in medulloblastoma, and are predominantly subgroup-enriched. The most common region of focal copy number gain is a tandem duplication of SNCAIP, a gene associated with Parkinson's disease, which is exquisitely restricted to Group 4 alpha. Recurrent translocations of PVT1, including PVT1-MYC and PVT1-NDRG1, that arise through chromothripsis are restricted to Group 3. Numerous targetable SCNAs, including recurrent events targeting TGF-beta signalling in Group 3, and NF-kappa B signalling in Group 4, suggest future avenues for rational, targeted therapy.

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Introduction: Denosumab, a fully human anti-RANKL monoclonal antibody, reduces the incidence of skeletal-related events in patients with bone metastases from solid tumors. We present survival data for the subset of patients with lung cancer, participating in the phase 3 trial of denosumab versus zoledronic acid (ZA) in the treatment of bone metastases from solid tumors (except breast or prostate) or multiple myeloma. Methods: Patients were randomized 1:1 to receive monthly subcutaneous denosumab 120 mg or intravenous ZA 4 mg. An exploratory analysis, using Kaplan-Meier estimates and proportional hazards models, was performed for overall survival among patients with non-small-cell lung cancer (NSCLC) and SCLC. Results: Denosumab was associated with improved median overall survival versus ZA in 811 patients with any lung cancer (8.9 versus 7.7 months; hazard ratio [HR] 0.80) and in 702 patients with NSCLC (9.5 versus 8.0 months; HR 0.78) (p = 0.01, each comparison). Further analysis of NSCLC by histological type showed a median survival of 8.6 months for denosumab versus 6.4 months for ZA in patients with squamous cell carcinoma (HR 0.68; p = 0.035). Incidence of overall adverse events was balanced between treatment groups; serious adverse events occurred in 66.0% of denosumab-treated patients and 72.9% of ZA-treated patients. Cumulative incidence of osteonecrosis of the jaw was similar between groups (0.7% denosumab versus 0.8% ZA). Hypocalcemia rates were 8.6% with denosumab and 3.8% with ZA. Conclusion: In this exploratory analysis, denosumab was associated with improved overall survival compared with ZA, in patients with metastatic lung cancer.

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This work introduces the phenomenon of Collective Almost Synchronisation (CAS), which describes a universal way of how patterns can appear in complex networks for small coupling strengths. The CAS phenomenon appears due to the existence of an approximately constant local mean field and is characterised by having nodes with trajectories evolving around periodic stable orbits. Common notion based on statistical knowledge would lead one to interpret the appearance of a local constant mean field as a consequence of the fact that the behaviour of each node is not correlated to the behaviours of the others. Contrary to this common notion, we show that various well known weaker forms of synchronisation (almost, time-lag, phase synchronisation, and generalised synchronisation) appear as a result of the onset of an almost constant local mean field. If the memory is formed in a brain by minimising the coupling strength among neurons and maximising the number of possible patterns, then the CAS phenomenon is a plausible explanation for it.

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For fixed positive integers r, k and E with 1 <= l < r and an r-uniform hypergraph H, let kappa(H, k, l) denote the number of k-colorings of the set of hyperedges of H for which any two hyperedges in the same color class intersect in at least l elements. Consider the function KC(n, r, k, l) = max(H epsilon Hn) kappa(H, k, l), where the maximum runs over the family H-n of all r-uniform hypergraphs on n vertices. In this paper, we determine the asymptotic behavior of the function KC(n, r, k, l) for every fixed r, k and l and describe the extremal hypergraphs. This variant of a problem of Erdos and Rothschild, who considered edge colorings of graphs without a monochromatic triangle, is related to the Erdos-Ko-Rado Theorem (Erdos et al., 1961 [8]) on intersecting systems of sets. (C) 2011 Elsevier Ltd. All rights reserved.

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Background In ROCKET AF, rivaroxaban was non-inferior to adjusted-dose warfarin in preventing stroke or systemic embolism among patients with atrial fibrillation (AF). We aimed to investigate whether the efficacy and safety of rivaroxaban compared with warfarin is consistent among the subgroups of patients with and without previous stroke or transient ischaemic attack (TIA). Methods In ROCKET AF, patients with AF who were at increased risk of stroke were randomly assigned (1:1) in a double-blind manner to rivaroxaban 20 mg daily or adjusted dose warfarin (international normalised ratio 2-0-3.0). Patients and investigators were masked to treatment allocation. Between Dec 18,2006, and June 17,2009,14 264 patients from 1178 centres in 45 countries were randomly assigned. The primary endpoint was the composite of stroke or non-CNS systemic embolism. In this substudy we assessed the interaction of the treatment effects of rivaroxaban and warfarin among patients with and without previous stroke or TIA. Efficacy analyses were by intention to treat and safety analyses were done in the on-treatment population. ROCKET AF is registered with ClinicalTrials.gov, number NCT00403767. Findings 7468 (52%) patients had a previous stroke (n=4907) or TIA (n=2561) and 6796 (48%) had no previous stroke or TIA. The number of events per 100 person-years for the primary endpoint in patients treated with rivaroxaban compared with warfarin was consistent among patients with previous stroke or TIA (2.79% rivaroxaban vs 2.96% warfarin; hazard ratio [HR] 0-94,95% CI 0.77-1.16) and those without (1.44% vs 1.88%; 0.77, 0.58-1-01; interaction p=0.23). The number of major and non-major clinically relevant bleeding events per 100 person-years in patients treated with rivaroxaban compared with warfarin was consistent among patients with previous stroke or TIA (13.31% rivaroxaban vs 13.87% warfarin; HR 0.96,95% CI 0.87-1-07) and those without (16.69% vs 15.19%; 1.10, 0.99-1.21; interaction p=0.08). Interpretation There was no evidence that the relative efficacy and safety of rivaroxaban compared with warfarin was different between patients who had a previous stroke or TIA and those who had no previous stroke or TIA. These results support the use of rivaroxaban as an alternative to warfarin for prevention of recurrent as well as initial stroke in patients with AF.

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Abstract Background The Zaprionus genus shares evolutionary features with the melanogaster subgroup, such as space and time of origin. Although little information about the transposable element content in the Zaprionus genus had been accumulated, some of their elements appear to be more closely related with those of the melanogaster subgroup, indicating that these two groups of species were involved in horizontal transfer events during their evolution. Among these elements, the Gypsy and the Micropia retroelements were chosen for screening in seven species of the two Zaprionus subgenera, Anaprionus and Zaprionus. Results Screening allowed the identification of diverse Gypsy and Micropia retroelements only in species of the Zaprionus subgenus, showing that they are transcriptionally active in the sampled species. The sequences of each retroelement were closely related to those of the melanogaster species subgroup, and the most parsimonious hypothesis would be that 15 horizontal transfer events shaped their evolution. The Gypsy retroelement of the melanogaster subgroup probably invaded the Zaprionus genomes about 11 MYA. In contrast, the Micropia retroelement may have been introduced into the Zaprionus subgenus and the melanogaster subgroup from an unknown donor more recently (~3 MYA). Conclusion Gypsy and Micropia of Zaprionus and melanogaster species share similar evolutionary patterns. The sharing of evolutionary, ecological and ethological features probably allowed these species to pass through a permissive period of transposable element invasion, explaining the proposed waves of horizontal transfers.

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Abstract Background The ability to successfully identify and incriminate pathogen vectors is fundamental to effective pathogen control and management. This task is confounded by the existence of cryptic species complexes. Molecular markers can offer a highly effective means of species identification in such complexes and are routinely employed in the study of medical entomology. Here we evaluate a multi-locus system for the identification of potential malaria vectors in the Anopheles strodei subgroup. Methods Larvae, pupae and adult mosquitoes (n = 61) from the An. strodei subgroup were collected from 21 localities in nine Brazilian states and sequenced for the COI, ITS2 and white gene. A Bayesian phylogenetic approach was used to describe the relationships in the Strodei Subgroup and the utility of COI and ITS2 barcodes was assessed using the neighbor joining tree and “best close match” approaches. Results Bayesian phylogenetic analysis of the COI, ITS2 and white gene found support for seven clades in the An. strodei subgroup. The COI and ITS2 barcodes were individually unsuccessful at resolving and identifying some species in the Subgroup. The COI barcode failed to resolve An. albertoi and An. strodei but successfully identified approximately 92% of all species queries, while the ITS2 barcode failed to resolve An. arthuri and successfully identified approximately 60% of all species queries. A multi-locus COI-ITS2 barcode, however, resolved all species in a neighbor joining tree and successfully identified all species queries using the “best close match” approach. Conclusions Our study corroborates the existence of An. albertoi, An. CP Form and An. strodei in the An. strodei subgroup and identifies four species under An. arthuri informally named A-D herein. The use of a multi-locus barcode is proposed for species identification, which has potentially important utility for vector incrimination. Individuals previously found naturally infected with Plasmodium vivax in the southern Amazon basin and reported as An. strodei are likely to have been from An. arthuri C identified in this study.

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The intermetallic compounds ScPdZn and ScPtZn were prepared from the elements by high-frequency melting in sealed tantalum ampoules. Both structures were refined from single crystal X-ray diffractometer data: YAlGe type, Cmcm, a = 429.53(8), b = 907.7(1), c = 527.86(1) pm, wR2 = 0.0375, 231 F2 values, for ScPdZn and a = 425.3(1), b = 918.4(2), c = 523.3(1) pm, wR2 = 0.0399, 213 F2 values for ScPtZn with 14 variables per refinement. The structures are orthorhombically distorted variants of the AlB2 type. The scandium and palladium (platinum atoms) build up ordered networks Sc3Pd3 and Sc3Pt3 (boron networks) which are slightly shifted with respect to each other. These networks are penetrated by chains of zinc atoms (262 pm in ScPtZn) which correspond to the aluminum positions, i.e. Zn(ScPd) and Zn(ScPt). The corresponding group-subgroup scheme and the differences in chemical bonding with respect to other AlB2-derived REPdZn and REPtZn compounds are discussed. 45Sc solid state NMR spectra confirm the single crystallographic scandium sites. From electronic band structure calculations the two compounds are found metallic with free electron like behavior at the Fermi level. A larger cohesive energy for ScPtZn suggests a more strongly bonded intermetallic than ScPdZn. Electron localization and overlap population analyses identify the largest bonding for scandium with the transition metal (Pd, Pt).