Comment on Solution of the Relativistic Dirac-Morse Problem

We do not think that the relativistic Morse potential problem has been correctly formulated and solved by Alhaidari (Phys. Rev. Lett. 87, 210405 (2001)).Comment: Revtex, 4 pages, preprint "Notas de F\'\i sica" CBPF-NF-011/02/Fev./200

Produção e composição química de aveia não irrigada em quatro épocas de corte.

A aveia preta e os cultivadores UPF2, UPF3 e UPF7 de aveia amarela foram avaliados durante o período de inverno, sem irrigação em Jaboticabal-SP. As plantas foram colhidas aos 51, 64, 77 e 90 dias após a semeadura. A produção de MS variou de 931,6 a 2378,3 kg/ha para aveia preta, de 903,4 a 3135,2 kg/ha para a cv. UPF2 de 439,7 a 3920,9 kg/ha para a cv. UPF3 e de 1003,7 a 4351.1 kg/ha para a cv. UPF7. Dos 51 aos 90 dias após a semeadura os teores de PB na folha decresceram, de 18,0% para 10,2%, e os de FDN aumentaram de 41,6% para 47,9%.Resumo expandid

Evaluation of Oat Genotypes for Forage and Seed Production in the Northeast Region of Sao Paulo State-Brazil

The DM production (DMP), chemical composition, and seed production of black oats (Avena strigosa Schreb.) and the yellow oat cultivars ‘UPF2’ , ‘UPF3’ and ‘UPF7’ (A. byzantina C. Kock.) were evaluated under two management systems: plants cut (60 days after sowing-DAS) and uncut for seed production. Oat genotypes were sown in 1993 and 1994. UPF7 was the least productive. No difference was detected (P \u3e 0.05) in the cell wall composition of the genotypes. High values of CP (22.9%) and IVDMD (77.6%) were determined across all genotypes. In 1994, cutting at 60 DAS affected the seed production of the cultivars. All oat genotypes presented satisfactory forage and grain production in both management systems. Seed production can be reduced in all genotypes evaluated due to variations in climatic conditions and leaf rust disease

On the connection of Gamma-rays, Dark Matter and Higgs searches at LHC

Motivated by the upcoming Higgs analyzes we investigate the importance of the complementarity of the Higgs boson chase on the low mass WIMP search in direct detection experiments and the gamma-ray emission from the Galactic Center measured by the Fermi-LAT telescope in the context of the $SU(3)_c\otimes SU(3)_L\otimes U(1)_N$. We obtain the relic abundance, thermal cross section, the WIMP-nucleon cross section in the low mass regime and network them with the branching ratios of the Higgs boson in the model. We conclude that the Higgs boson search has a profound connection to the dark matter problem in our model, in particular for the case that ($M_{WIMP} < 60$ GeV) the BR($H \rightarrow 2$ WIMPs) $\gtrsim 90$. This scenario could explain this plateau of any mild excess regarding the Higgs search as well as explain the gamma-ray emission from the galactic center through the $b\bar{b}$ channel with a WIMP in the mass range of 25-45 GeV, while still being consistent with the current limits from XENON100 and CDMSII. However, if the recent modest excesses measured at LHC and TEVATRON are confirmed and consistent with a standard model Higgs boson this would imply that $M_{WIMP} > 60$ GeV, consequently ruling out any attempt to explain the Fermi-LAT observations.Comment: 8 pages, 9 figure

Potencial alelopático de forrageiras tropicais: efeitos sobre invasoras de pastagens.

Extratos aquosos de sementes, parte aérea e raízes de três gramíneas e três leguminosas forrageiras foram preparados a uma concentração de 10%, com o objetivo de avaliar os efeitos potencialmente alelopáticos sobre a germinação de sementes e o alongamento da radícula das invasoras de pastagens: desmódio, guanxuma e as sa-pe ix e. A germinação foi monitorada em períodos de dez dias, com contagens diárias e eliminação das sementes germinadas. O alongamento da radícula era medido ao final de um período de dez dias de crescimento. Os efeitos do potencial osmótico foram isolados através de cálculos. As espécies doadoras evidenciaram potencialidades alelopáticas que variou de intensidade em função da especificidade entre espécies doadoras e receptoras. B. brizantha e calopogônio foram as espécies que promoveram as reduções mais intensas sobre a germinação das sementes e o alongamento da radícula das espécies receptoras. A parte aérea das espécies doadoras constituiu-se na principal fonte de substâncias potencialmente alelopáticas, solúveis em água. Independentemen te da espécie doadora, desmódio e guanxuma foram as invasoras que se mostraram mais susceptíveis aos efeitos potencialmente alelopáticos, enquanto o assa-peixe foi a mais tolerante

Dry Matter Production of Shoots and Root Density of Two Cultivars of \u3ci\u3eLablab purpureus\u3c/i\u3e (L.) Sweet

This experiment was conducted in green house conditions to evaluate the DM accumulation in the shoots and in the roots of two cultivars of Lablab purpureus (L.) Sweet. A 2x3 factorial (two cultivars and three evaluation dates) was conducted according to a randomized complete block design with four replications, being the cultivars Highworth and Rongai evaluated at 42, 56, and 70 days after seedling emergence (DASE). The results indicated that the cvs. Highworth and Rongai have the same pattern of DM accumulation in the shoots. In the upper layer of the soil (0-0.20 m) it was found 38.83% and 43.64% of the DM accumulated in the roots down to 2.00 m depth, in the cvs. Highworth and Rongai, respectively. In the deepest layer (1.80-2.00 m) it was found 3.02% and 1.5% of the DM accumulated in the roots of the cvs. Highworth and Rongai, respectively. The root density showed a striking decrease upper layer from the soil (0-0.2 m) down to the depth of 0.60 - 0.80 m (from 10.83 to 1.75 cm.cm-3 in the cv. Highworth and from 10.76 to 1.28 cm.cm-3 in the cv. Rongai). At the bottom layer (1.80-2.00 m) the root density values were 0.98 cm.cm-3 and 0.59 cm.cm-3, respectively for the cvs. Highworth and Rongai. The root/shoot ratios were similar in both cvs. and decreased from 42 to 70 DASE showing that the cvs. evaluated had the same dynamics of DM accumulation

Dirac-Hestenes spinor fields in Riemann-Cartan spacetime

In this paper we study Dirac-Hestenes spinor fields (DHSF) on a four-dimensional Riemann-Cartan spacetime (RCST). We prove that these fields must be defined as certain equivalence classes of even sections of the Clifford bundle (over the RCST), thereby being certain particular sections of a new bundle named Spin-Clifford bundle (SCB). The conditions for the existence of the SCB are studied and are shown to be equivalent to the famous Geroch's theorem concerning to the existence of spinor structures in a Lorentzian spacetime. We introduce also the covariant and algebraic Dirac spinor fields and compare these with DHSF, showing that all the three kinds of spinor fields contain the same mathematical and physical information. We clarify also the notion of (Crumeyrolle's) amorphous spinors (Dirac-K\"ahler spinor fields are of this type), showing that they cannot be used to describe fermionic fields. We develop a rigorous theory for the covariant derivatives of Clifford fields (sections of the Clifford bundle (CB)) and of Dirac-Hestenes spinor fields. We show how to generalize the original Dirac-Hestenes equation in Minkowski spacetime for the case of a RCST. Our results are obtained from a variational principle formulated through the multiform derivative approach to Lagrangian field theory in the Clifford bundle.Comment: 45 pages, special macros kapproc.sty and makro822.te