Importância de Fatores Ecológicos, Filogenéticos e Alométricos na Variação da Forma do Crânio Roedores

Rodentia é a ordem de mamíferos mais diversa em todo o Mundo, padrão que é observado principalmente nos Neotrópicos, incluso o Brasil, conforme as listas de espécies a nível regional e nacional. Possui distribuição cosmopolita com grande diversidade de dietas e hábitos locomotores. Suas sinapomorfias-chave são características cranianas e dentais, portanto neste trabalho o crânio foi utilizado como objeto de estudo, analisando sua interação com fatores alométricos, dieta, sexo e parentesco. As 32 espécies estudadas ocorrem no Espírito Santo e são pertencentes a 7 famílias da ordem. A ferramenta utilizada nessa investigação foi a morfometria geométrica, utilizando nas análises dos dados testes estatísticos multivariados, análises discriminantes, regressões e análise das variáveis canônicas. Não foi verificado dimorfismo sexual quando todas as espécies são analisadas, porém há diferenciação na forma e tamanho do crânio. A comparação entre os herbívoros e insetívoros mostrou que há diferenças morfológicas entre as espécies com dietas diferentes, mesmo quando elas possuem parentesco filogenético. Ainda assim as árvores quando reconstruídas, com base nos caracteres cranianos, tiveram o mesmo resultado em todas as vistas avaliadas, tanto do crânio quanto mandíbula, conseguindo manter praticamente todas as relações de parentesco entre as famílias corretamente (exceto Sciuridae e Dasyproctidae). A alometria, entretanto, não é um fator de variação no crânio de roedores, alcançando valores desprezíveis de regressão, porém esse trabalho mostrou ser possível diferenciar diferentes tipos de dieta e relações de parentesco pela morfometria geométrica do crânio de roedores

Topological Vector Symmetry of BRSTQFT and Construction of Maximal Supersymmetry

The scalar and vector topological Yang-Mills symmetries determine a closed and consistent sector of Yang-Mills supersymmetry. We provide a geometrical construction of these symmetries, based on a horizontality condition on reducible manifolds. This yields globally well-defined scalar and vector topological BRST operators. These operators generate a subalgebra of maximally supersymmetric Yang-Mills theory, which is small enough to be closed off-shell with a finite set of auxiliary fields and large enough to determine the Yang-Mills supersymmetric theory. Poincar\'e supersymmetry is reached in the limit of flat manifolds. The arbitrariness of the gauge functions in BRSTQFTs is thus removed by the requirement of scalar and vector topological symmetry, which also determines the complete supersymmetry transformations in a twisted way. Provided additional Killing vectors exist on the manifold, an equivariant extension of our geometrical framework is provided, and the resulting "equivariant topological field theory" corresponds to the twist of super Yang-Mills theory on Omega backgrounds.Comment: 50 page

A new picture on (3+1)D topological mass mechanism

We present a class of mappings between the fields of the Cremmer-Sherk and pure BF models in 4D. These mappings are established by two distinct procedures. First a mapping of their actions is produced iteratively resulting in an expansion of the fields of one model in terms of progressively higher derivatives of the other model fields. Secondly an exact mapping is introduced by mapping their quantum correlation functions. The equivalence of both procedures is shown by resorting to the invariance under field scale transformations of the topological action. Related equivalences in 5D and 3D are discussed. A cohomological argument is presented to provide consistency of the iterative mapping.Comment: 13 page

Two loop effective potential for < A^2_\mu > in the Landau gauge in quantum chromodynamics

We construct the effective potential for the dimension two composite operator 1/2 A^{a 2}_\mu in QCD with massless quarks in the Landau gauge for an arbitrary colour group at two loops. For SU(3) we show that an estimate for the effective gluon mass decreases as N_f increases.Comment: 17 latex page

Ghost Condensates and Dynamical Breaking of SL(2,R) in Yang-Mills in the Maximal Abelian Gauge

Ghost condensates of dimension two in SU(N) Yang-Mills theory quantized in the Maximal Abelian Gauge are discussed. These condensates turn out to be related to the dynamical breaking of the SL(2,R) symmetry present in this gaugeComment: 16 pages, LaTeX2e, final version to appear in J. Phys.

Perturbing Topological Field Theories

The abelian Chern-Simons theory is perturbed by introducing local gauge-invariant interaction terms depending on the curvature. The computation of the correlation function of two Wilson lines for two smooth closed nonintersecting curves is reported up to four loops and is shown to be unaffected by radiative corrections. This result ensures the stability of the linking number of the two curves with respect to the local perturbations which may be added to the Chern-Simons action.Comment: 13 pages, 5 figures, corrected some typo

Conceptualising nature-based solutions: addressing environmental challenges in the city of Amman, Jordan

This article explores the conceptualisation and applicability of nature-based solutions (NBS) in the semi-arid context of Amman, Jordan. Through a Delphi survey, interviews and literature review, it investigates local experts’ views, concluding that NBS are a viable approach, even in context of water scarcity and high urban temperatures. Our results advocate for a paradigm shift towards a balanced relationship between urbanisation and nature, the integration of nature-based thinking into educational systems and continuous development and training for planners and local officers. Cross-sector collaboration, a solid participatory framework, and financial mechanisms for pilot cases are essential for this transformative shift

Enhanced production of oxidised mercury over the tropical Pacific Ocean: A key missing oxidation pathway

Mercury is a contaminant of global concern. It is transported in the atmosphere primarily as gaseous elemental mercury, but its reactivity and deposition to the surface environment, through which it enters the aquatic food chain, is greatly enhanced following oxidation. Measurements and modelling studies of oxidised mercury in the polar to sub-tropical marine boundary layer (MBL) have suggested that photolytically produced bromine atoms are the primary oxidant of mercury. We report year-round measurements of elemental and oxidised mercury, along with ozone, halogen oxides (IO and BrO) and nitrogen oxides (NO2), in the MBL over the Galápagos Islands in the equatorial Pacific. Elemental mercury concentration remained low throughout the year, while higher than expected levels of oxidised mercury occurred around midday. Our results show that the production of oxidised mercury in the tropical MBL cannot be accounted for by bromine oxidation only, or by the inclusion of ozone and hydroxyl. As a two-step oxidation mechanism, where the HgBr intermediate is further oxidised to Hg(II), depends critically on the stability of HgBr, an additional oxidant is needed to react with HgBr to explain more than 50% of the observed oxidised mercury. Based on best available thermodynamic data, we show that atomic iodine, NO2, or HO2 could all play the potential role of the missing oxidant, though their relative importance cannot be determined explicitly at this time due to the uncertainties associated with mercury oxidation kinetics. We conclude that the key pathway that significantly enhances atmospheric mercury oxidation and deposition to the tropical oceans is missing from the current understanding of atmospheric mercury oxidation