55 research outputs found

    Review of Dysmorphoptilidae Handlirsch (Hemiptera: Cicadomorpha) from the Argentinean Triassic, with description of a new subfamily, and a new species

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    This contribution presents new fossil insect taxa of the order Hemiptera (Cicadomorpha, Dysmorphoptilidae, Gallegomorphoptilinae subfam. n.) from the Ischichuca Formation (late Middle Triassic to early Late Triassic) from La Rioja Province (Argentina). One subfamily, one new species, and three new combinations, are proposed: Gallegomorphoptila kotejai sp. n., G. acostai comb. n., G. gigantea comb. n., G. pulcherrima comb. n. Also, a wide review of the family Dysmorphoptilidae HANDLIRSCH (diverse and well represented in the Argentinean Triassic levels), is madeFil: Martins-Neto, R.G.. Universidade Federal de Juiz de Fora, Minas Gerais; BrasilFil: Gallego, Oscar Florencio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

    Remarks on the neuropterofauna (Insecta, Neuroptera) from the Brazilian Cretaceous, with keys for the identification of the known taxa

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    This paper reviews all previous knowledge about neuropterans from the Santana Formation (Lower Cretaceous, northeastern Brazil) involving a decade of research in this group. The neuropterofauna from Santana Formation is one of the most complete and diverse known, formed by 50 species distributed in 28 genera, representing 11 families: Ascalaphidae, Myrmeleontidae, Psychopsidae, Chrysopidae, Berothidae, Sisyridae, Nemopteridae, Roeslerianidae, Babinskaiidae, Paleoleontidae and Makarkiniidae. All the know n material is from the laminated limestone, tip of the Crato Member, lowest unit of the Santana Formation, Lower Cretaceous, Ceará State, northeastern Brazil. This research have the objective to furnish the keys for the identification of all known Brazilian fossil neuropterans and 16 Figures containing the drafts of all Brazilian neuropterans holotypes

    Checklist of South American Cenozoic Insects

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    This checklist is a compilation of literature about South American Cenozoic insects. The list include 73 named insects belonging to 11 orders. Records are from the  Oligocene and Pleistocene of south-eastern Brazil, late Paleocene of north-western Argentina and Paleocene-Eocene of southern Argentina

    Finite-Temperature Transport in Finite-Size Hubbard Rings in the Strong-Coupling Limit

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    We study the current, the curvature of levels, and the finite temperature charge stiffness, D(T,L), in the strongly correlated limit, U>>t, for Hubbard rings of L sites, with U the on-site Coulomb repulsion and t the hopping integral. Our study is done for finite-size systems and any band filling. Up to order t we derive our results following two independent approaches, namely, using the solution provided by the Bethe ansatz and the solution provided by an algebraic method, where the electronic operators are represented in a slave-fermion picture. We find that, in the U=\infty case, the finite-temperature charge stiffness is finite for electronic densities, n, smaller than one. These results are essencially those of spinless fermions in a lattice of size L, apart from small corrections coming from a statistical flux, due to the spin degrees of freedom. Up to order t, the Mott-Hubbard gap is \Delta_{MH}=U-4t, and we find that D(T) is finite for n<1, but is zero at half-filling. This result comes from the effective flux felt by the holon excitations, which, due to the presence of doubly occupied sites, is renormalized to \Phi^{eff}=\phi(N_h-N_d)/(N_d+N_h), and which is zero at half-filling, with N_d and N_h being the number of doubly occupied and empty lattice sites, respectively. Further, for half-filling, the current transported by any eigenstate of the system is zero and, therefore, D(T) is also zero.Comment: 15 pages and 6 figures; accepted for PR

    Amyloid and tau pathology associations with personality traits, neuropsychiatric symptoms, and cognitive lifestyle in the preclinical phases of sporadic and autosomal dominant Alzheimer’s disease

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    Background Major prevention trials for Alzheimer’s disease (AD) are now focusing on multidomain lifestyle interventions. However, the exact combination of behavioral factors related to AD pathology remains unclear. In 2 cohorts of cognitively unimpaired individuals at risk of AD, we examined which combinations of personality traits, neuropsychiatric symptoms, and cognitive lifestyle (years of education or lifetime cognitive activity) related to the pathological hallmarks of AD, amyloid-β, and tau deposits. Methods A total of 115 older adults with a parental or multiple-sibling family history of sporadic AD (PREVENT-AD [PRe-symptomatic EValuation of Experimental or Novel Treatments for AD] cohort) underwent amyloid and tau positron emission tomography and answered several questionnaires related to behavioral attributes. Separately, we studied 117 mutation carriers from the DIAN (Dominant Inherited Alzheimer Network) study group cohort with amyloid positron emission tomography and behavioral data. Using partial least squares analysis, we identified latent variables relating amyloid or tau pathology with combinations of personality traits, neuropsychiatric symptoms, and cognitive lifestyle. Results In PREVENT-AD, lower neuroticism, neuropsychiatric burden, and higher education were associated with less amyloid deposition (p = .014). Lower neuroticism and neuropsychiatric features, along with higher measures of openness and extraversion, were related to less tau deposition (p = .006). In DIAN, lower neuropsychiatric burden and higher education were also associated with less amyloid (p = .005). The combination of these factors accounted for up to 14% of AD pathology. Conclusions In the preclinical phase of both sporadic and autosomal dominant AD, multiple behavioral features were associated with AD pathology. These results may suggest potential pathways by which multidomain interventions might help delay AD onset or progression
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