Electromagnetic corrections in the anomaly sector

Chiral perturbation theory in the anomaly sector for $N_f=2$ is extended to include dynamical photons, thereby allowing a complete treatment of isospin breaking. A minimal set of independent chiral lagrangian terms is determined and the divergence structure is worked out. There are contributions from irreducible and also from reducible one-loop graphs, a feature of ChPT at order larger than four. The generating functional is non-anomalous at order $e^2p^4$, but not necessarily at higher order in $e^2$. Practical applications to $\gamma\pi\to\pi\pi$ and to the $\pi^0\to2\gamma$ amplitudes are considered. In the latter case, a complete discussion of the corrections beyond current algebra is presented including quark mass as well as electromagnetic effects.Comment: 26 pages, 3 figure

Prevendo o crescimento da produção industrial usando um número limitado de combinações de previsões

The purpose of this article is to propose and evaluate forecasting models for the Brazilian industrial GDP. Most models are based on vector auto-regressions (VARs) or on restricted VARs, but models on the ARMA class are also entertained. We used many forecasting models and also combinations of these models. The use of cointegration vectors improves substantially the forecast performance of industrial GDP. Furthermore, in general, combining models out-performed individual models, even when the performance of the later was acceptable.O objetivo central deste artigo é o de propor e avaliar modelos econométricos de previsão para o PIB industrial brasileiro. Para tanto, foram utilizados diversos modelos de previsão como também combinações de modelos. Foi realizada uma análise criteriosa das séries a serem utilizadas na previsão. Nós concluímos que a utilização de vetores de cointegração melhora substancialmente a performance da previsão. Além disso, os modelos de combinação de previsão, na maioria dos casos, tiveram uma performance superior aos demais modelos, que já apresentavam boa capacidade preditiva

Novo indicador coincidente para a atividade industrial brasileira

In this paper we perform and evaluate, in sample, some methodologies for building of coincident indicators focusing on the detection of business cycle of the Industrial activity. Specifically, we try a version of coincident indicator based on the coincident indicator for economy of the TCB (The Conference Board), a modified version in which the volatility is modeled, a Stock-Watson approach and a Mariano-Murasawa approach. We conclude that, in general, the TCB index out-performs the others methods tested, being competitive just with the modified method. Furthermore, The TCB Traditional has the tendency to comprehend the recessives periods of the others, in correspondence with the known recessive periods for industrial activity.Neste trabalho aplicam-se e testam-se, dentro da amostra, algumas metodologias de construção de indicadores coincidentes para atividade industrial visando à detecção de ciclos de crescimento/recessão da atividade industrial. Especificamente, testou-se uma versão baseada no indicador coincidente do The Conference Board (TCB), uma versão modificada deste, na qual as volatilidades são modeladas, a abordagem de Stock-Watson tradicional e, finalmente, testou-se a abordagem de Mariano-Murasawa. Concluiu-se que, em geral, o índice TCB padrão é superior a outros métodos testados, sendo apenas competitivo com o método modificado. Mais ainda, o índice TCB tende a englobar os períodos recessivos apresentados pelos outros índices, sendo correspondentes com os períodos recessivos conhecidos do setor industrial

A missense mutation in Ehd1 associated with defective spermatogenesis and male infertility

Normal function of the C-terminal Eps15 homology domain-containing protein 1 (EHD1) has previously been associated with endocytic vesicle trafficking, shaping of intracellular membranes, and ciliogenesis. We recently identified an autosomal recessive missense mutation c.1192C>T (p.R398W) of EHD1 in patients who had low molecular weight proteinuria (0.7–2.1 g/d) and high-frequency hearing loss. It was already known from Ehd1 knockout mice that inactivation of Ehd1 can lead to male infertility. However, the exact role of the EHD1 protein and its p.R398W mutant during spermatogenesis remained still unclear. Here, we report the testicular phenotype of a knockin mouse model carrying the p.R398W mutation in the EHD1 protein. Male homozygous knockin mice were infertile, whereas the mutation had no effect on female fertility. Testes and epididymes were significantly reduced in size and weight. The testicular epithelium appeared profoundly damaged and had a disorganized architecture. The composition of developing cell types was altered. Malformed acrosomes covered underdeveloped and misshaped sperm heads. In the sperm tail, midpieces were largely missing indicating disturbed assembly of the sperm tail. Defective structures, i.e., nuclei, acrosomes, and sperm tail midpieces, were observed in large vacuoles scattered throughout the epithelium. Interestingly, cilia formation itself did not appear to be affected, as the axoneme and other parts of the sperm tails except the midpieces appeared to be intact. In wildtype mice, EHD1 co-localized with acrosomal granules on round spermatids, suggesting a role of the EHD1 protein during acrosomal development. Wildtype EHD1 also co-localized with the VPS35 component of the retromer complex, whereas the p.R398W mutant did not. The testicular pathologies appeared very early during the first spermatogenic wave in young mice (starting at 14 dpp) and tubular destruction worsened with age. Taken together, EHD1 plays an important and probably multifaceted role in spermatogenesis in mice. Therefore, EHD1 may also be a hitherto underestimated infertility gene in humans

Anomalies and WZW-term of two-flavour QCD

The U(2)_R x U(2)_L symmetry of QCD with two massless flavours is subject to anomalies which affect correlation functions involving the singlet currents A^0_\mu or V^0_\mu. These are relevant for pion-photon interactions, because - for two flavours - the electromagnetic current contains a singlet piece. We give the effective Lagrangian required for the corresponding low energy analysis to next-to-leading order, without invoking an expansion in the mass of the strange quark. In particular, the Wess-Zumino-Witten term that accounts for the two-flavour anomalies within the effective theory is written down in closed form.Comment: 17 pages, 1 figur

Mir-132/212 is required for maturation of binocular matching of orientation preference and depth perception

MicroRNAs (miRNAs) are known to mediate post-transcriptional gene regulation, but their role in postnatal brain development is still poorly explored. We show that the expression of many miRNAs is dramatically regulated during functional maturation of the mouse visual cortex with miR-132/212 family being one of the top upregulated miRNAs. Age-downregulated transcripts are significantly enriched in miR-132/miR-212 putative targets and in genes upregulated in miR-132/212 null mice. At a functional level, miR-132/212 deletion affects development of receptive fields of cortical neurons determining a specific impairment of binocular matching of orientation preference, but leaving orientation and direction selectivity unaltered. This deficit is associated with reduced depth perception in the visual cliff test. Deletion of miR-132/212 from forebrain excitatory neurons replicates the binocular matching deficits. Thus, miR-132/212 family shapes the age-dependent transcriptome of the visual cortex during a specific developmental window resulting in maturation of binocular cortical cells and depth perception

Common Trends and Common Cycles in Canada: Who Knew So Much Has Been Going On?

It is generally accepted that convergence is well established for regional Canadian per capita outputs. The authors present evidence that long-run movements are driven by two stochastic common trends in this time series. This evidence casts doubt on the convergence hypothesis for Canada. Another prevalent belief is that Canada forms an optimal currency area (OCA). The authors uncover three serially correlated common cycles whose asymmetries suggest Canada is not an OCA. Their common trend-common cycle decomposition of regional outputs also reveals that trend shocks dominate fluctuations in Ontario, Quebec, and the Maritimes in the short run and long run but not in British Columbia and the Prairie region. Thus, regional Canadian economic fluctuations are driven by a rich, diverse, and economically important set of propagation and growth mechanisms

Recent Developments in Chiral Perturbation Theory

I review recent developments in chiral perturbation theory (CHPT) which is the effective field theory of the standard model below the chiral symmetry breaking scale. The effective chiral Lagrangian formulated in terms of the pseudoscalar Goldstone bosons ($\pi, \, K, \, \eta$) is briefly discussed. It is shown how one can gain insight into the ratios of the light quark masses and to what extent these statements are model--independent. A few selected topics concerning the dynamics and interactions of the Goldstone bosons are considered. These are $\pi \pi$ and $\pi K$ scattering, some non--leptonic kaon decays and the problem of strong pionic final state interactions. CHPT also allows to make precise statements about the temperature dependence of QCD Green functions and the finite size effects related to the propagation of the (almost) massless pseudoscalar mesons. A central topic is the inclusion of matter fields, baryon CHPT. The relativistic and the heavy fermion formulation of coupling the baryons to the Goldstone fields are discussed. As applications, photo--nucleon processes, the $\pi N$ $\Sigma$--term and non--leptonic hyperon decays are presented. Implications of the spontaneously broken chiral symmetry on the nuclear forces and meson exchange currents are also described. Finally, the use of effective field theory methods in the strongly coupled Higgs sector and in the calculation of oblique electroweak corrections is touched upon.Comment: TeX, 110 pages, 15 figures available upon request, BUTP-93/0