The strong coupling regime of twelve flavors QCD

We summarize the results recently reported in Ref.[1] [A. Deuzeman, M.P. Lombardo, T. Nunes da Silva and E. Pallante,"The bulk transition of QCD with twelve flavors and the role of improvement"] for the SU(3) gauge theory with Nf=12 fundamental flavors, and we add some numerical evidence and theoretical discussion. In particular, we study the nature of the bulk transition that separates a chirally broken phase at strong coupling from a chirally restored phase at weak coupling. When a non-improved action is used, a rapid crossover is observed at small bare quark masses. Our results confirm a first order nature for this transition, in agreement with previous results we obtained using an improved action. As shown in Ref.[1], when improvement of the action is used, the transition is preceded by a second rapid crossover at weaker coupling and an exotic phase emerges, where chiral symmetry is not yet broken. This can be explained [1] by the non hermiticity of the improved lattice Transfer matrix, arising from the competition of nearest-neighbor and non-nearest neighbor interactions, the latter introduced by improvement and becoming increasingly relevant at strong coupling and coarse lattices. We further comment on how improvement may generally affect any lattice system at strong coupling, be it graphene or non abelian gauge theories inside or slightly below the conformal window.Comment: 7 pages, 7 figures, Proceedings of the 30th International Symposium on Lattice Field Theory, June 24 - 29, 2012, Cairns, Australi

Ripples and Grains Segregation on Unpaved Road

Ripples or corrugations are common phenomena observed in unpaved roads in less developed countries or regions. They cause several damages in vehicles leading to increased maintenance and product costs. In this paper, we present a computational study about the so-called washboard roads. Also, we study grain segregation on unpaved roads. Our simulations have been performed by the Discrete Element Method (DEM). In our model, the grains are regarded as soft disks. The grains are subjected to a gravitational field and both translational and rotational movements are allowed. The results show that wheels' of different sizes, weights and moving with different velocities can change corrugations amplitude and wavelength. Our results also show that some wavelength values are related to specific wheels' speed intervals. Segregation has been studied in roads formed by three distinct grain diameters distribution. We observed that the phenomenon is more evident for higher grain size dispersion

Conformal or Confining

We present a lattice study of the phase transitions at zero and nonzero temperature for the $SU(3)$ gauge theory with a varying number of flavours $N_f$ in the fundamental representation of the gauge group. We show that all results are consistent with a lower edge of the conformal window between $N_f=8$ and $N_f=6$. A lower edge in this interval is in remarkable agreement with perturbation theory and recent large-$N$ arguments. .Comment: 5 pages, 5 figures. New results added, conclusions strengthened. Scalar glueball now treated in a separate articl

The scalar glueball operator, the a-theorem, and the onset of conformality

We show that the anomalous dimension $\gamma_G$ of the scalar glueball operator contains information on the mechanism that leads to the onset of conformality at the lower edge of the conformal window in a non-Abelian gauge theory. In particular, it distinguishes whether the merging of an UV and an IR fixed point -- the simplest mechanism associated to a conformal phase transition and preconformal scaling -- does or does not occur. At the same time, we shed light on new analogies between QCD and its supersymmetric version. In SQCD, we derive an exact relation between $\gamma_G$ and the mass anomalous dimension $\gamma_m$, and we prove that the SQCD exact beta function is incompatible with merging as a consequence of the $a$-theorem; we also derive the general conditions that the latter imposes on the existence of fixed points, and prove the absence of an UV fixed point at nonzero coupling above the conformal window of SQCD. Perhaps not surprisingly, we then show that an exact relation between $\gamma_G$ and $\gamma_m$, fully analogous to SQCD, holds for the massless Veneziano limit of large-N QCD. We argue, based on the latter relation, the $a$-theorem, perturbation theory and physical arguments, that the incompatibility with merging may extend to QCD.Comment: 11 pages, 2 figures; some imprecisions in the notation fixed, version published in PL

Tratamento das cefaleias autonômicas refratárias em pacientes submetidos à neurocirurgia para tumor de hipófise

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2012.A incidência de cefaleia em pacientes com adenomas hipofisários é alta, e a fisiopatologia deste sintoma não é completamente conhecida. Embora a maioria dos pacientes tenha seu sintoma de cefaleia resolvido com o tratamento da lesão hipofisária, uma minoria de pacientes persiste com dor de forte intensidade, não responsiva aos tratamentos medicamentosos convencionais. No presente trabalho, nós testamos a eficácia do bloqueio percutâneo do gânglio de gasser e da rizotomia trigeminal como tratamento das cefaleias de padrão autonômico/trigeminal associada a adenomas hipofisários. Onze pacientes previamente tratados cirurgicamente para tumores hipofisários e que desenvolveram cefaleia autonômica de padrão intratável foram selecionados para participar do estudo, após serem submetidos à análise funcional com SPECT ictal. Inicialmente, todos os pacientes foram submetidos a um período de seis meses de tratamento clínico medicamentoso supervisionado. Os pacientes que não responderam a este tratamento após análise seriada de severidade da cefaleia, utilizando o Teste de Impacto de Cefaleia (Headache Impact Test – HIT-6), foram selecionados para realizar o procedimento de bloqueio percutâneo do gânglio de gasser. Dois pacientes foram posteriormente submetidos à rizotomia do gânglio trigeminal por cateter balão de Fogarty. Dos 11 pacientes estudados, seis não obtiveram melhora nos padrões da escala HIT-6 após seis meses de tratamento conservador, e foram submetidos ao bloqueio do gânglio de gasser. Após o bloqueio, significativa melhora foi verificada em três pacientes, com resposta positiva em longo prazo em um deles. Os outros dois, que obtiveram resposta transitória ao bloqueio ganglionar, foram submetidos à rizotomia trigeminal, com excelente resposta ao procedimento. O SPECT cerebral mostrou aumento da captação em região talâmica/hipotalâmica nos pacientes que responderam à manipulação do sistema trigemino-hipotalâmico. Em conclusão, o bloqueio percutâneo do gânglio de gasser e a rizotomia trigeminal por uso de cateter-balão de Fogarty parecem ser alternativas promissoras no tratamento das cefaleias severas, em pacientes selecionados, portadores de tumores hipofisários. ______________________________________________________________________________ ABSTRACTThe incidence of headache in patients with pituitary adenomas is high, and the underlying pathological mechanisms are not completely understood. Although most of the patients have their headache aborted after treatment of the pituitary tumor, a minority of patients persists with severe pain, and do not respond to conventional medication regimens. We tested the efficacy of percutaneous ganglion block and trigeminal rhizotomy on the treatment of severe trigeminal/autonomic headache associated with pituitary tumors. 11 patients treated surgically for pituitary adenomas who developed intractable trigeminal headaches were enrolled in the study, and submitted to ictal cerebral SPECT before starting treatment. Initially, all patients were submitted to a 6-month medical treatment trial. Patients who did not experience improvement in the headache severity, addressed by the Headache Impact Test-6 (HIT-6) scale, underwent trigeminal percutaneous ganglion blockade. Two patients were subsequently submitted to trigeminal balloon rhizotomy. Among the 11 patients, 6 did not have their HIT-6 scores improved after 6 months of treatment with medications, and underwent trigeminal ganglion blockade. Significant improvement in the headache severity was noted in three of them. Long-term response was obtained in one patient, and the other two, in whom the response was transient, were then successfully treated with trigeminal rhizotomy. Cerebral SPECT showed increased uptake in the thalamus/hypothalamus region, in patients who responded well to manipulation of the trigeminal-hypothalamic system. Percutaneous ganglion blockade and trigeminal rhizotomy may be promising alternative options for the treatment of severe headache, in selected patients with pituitary adenomas

QUEM DEFINE O SERVIÇO SOCIAL NO MUNDO

Resumo O artigo apresenta as principais contribuições do trabalho de dissertação homônimo ao debate dos fundamentos do Serviço Social em nível internacional. Abordamos a construção da chave analítica para a compreensão do encadeamento entre as determinações de escalas nacional e internacional na origem e desenvolvimento do Serviço Social, e que consiste na função intelectual do assistente social, compreendida como variável da disputa de hegemonia na ordem monopólica imperialista. Discutimos como as concepções de Serviço Social presentes na Definição da FITS influenciaram a tradição conservadora da profissão no Brasil e restante da América Latina ao longo da história, estabelecendo um nexo orgânico de continuidade com o conservadorismo a nível internacional. Enfim, traçamos o significado histórico do debate em torno da revisão da Definição, encampado pela articulação dos países latino-americanos e, em meio ao qual, a ONU emerge como o aparelho privado de hegemonia que efetivamente define o Serviço Social no mundo