Efeito da Spodoptera frugiperda em diferentes estádios de crescimento da cultura de milho

Research was conducted in Lafayette, Indiana, USA, in 1978 and 1979 to study the effect of fall armyworm, Spodoptera frugiperda on corn productivity. Artificial infestation was made on five growth stages of corn: 4-6 leaves, 8-10 leaves, 12-14 leaves, tassel and silk. Infestation was achieved by placing one fall armyworm egg mass per plant. One egg mass contained approximately 50 eggs. A physical barrier was used to avoid movement of larvae between experimental plots. Parameters evaluated were leaf damage. 20 days after infestation, ear damage, ear length, grain weight and grain number. Based on the results it was concluded that the most susceptible stage of growth was the 8-10 leaf stage, that is, approximately 40 days from the planting time. Infestation at this stage caused an average yield reduction of 18.7 percent. An average yield reduction of 6.6, 7.6 and 8.6 percent was obtained from plots infested at the 4-6 leaf, tassel and 12-14 leaf stages, respectively. No yield reduction occured at the silking stage. An average reduction of 18.4 percent on the number of grain obtained from plots infested at the 8-10 leaf stage was the main factor contributing to the greater yield reduction in that plot.Pesquisas foram realizadas em Lafayette, Indiana, USA, durante os períodos de 1978 e 1979, para estudar os efeitos da lagarta-do-cartucho, Spodoptera frugiperda, na produtividade do milho. Infestação artificial foi feita em cinco diferentes estádios de crescimento da cultura: 4 - 6 folhas, 8 - 10 folhas, 12 - 14 folhas, pendoamento e embonecamento. A infestação foi realizada colocando-se em cada planta uma massa de ovos contendo aproximadamente 50 ovos. Para evitar o movimento das larvas entre as parcelas, construiu-se uma barreira física. Os parâmetros avaliados foram: danos nas folhas, 20 dias após a infestação; danos causados às espigas; tamanho das espigas; produção por planta; e o peso e número de grãos. Com base nos resultados, concluiu-se que o estádio de crescimento mais susceptível à lagarta do cartucho foi o de 8- 10 folhas, ou seja, aproximadamente 40 dias após o plantio. A redução na produtividade, para infestações neste estádio, foi de 18,7%. Nas parcelas infestadas nos estádios de 4 - 6 folhas, pendoamento e 12 - 14 folhas, a redução foi de 6,6, 7,6 e 8,6%, respectivamente. Nenhuma redução foi verificada no estádio de embonecamento. Uma redução média de 18,4% no número de grãos nas parcelas infestadas no estádio de 8 - 10 folhas foi o principal fator que contribuiu para a menor produção naquele tratamento

Blue-detuned optical ring trap for Bose-Einstein condensates based on conical refraction

We present a novel approach for the optical manipulation of neutral atoms in annular light structures produced by the phenomenon of conical refraction occurring in biaxial optical crystals. For a beam focused to a plane behind the crystal, the focal plane exhibits two concentric bright rings enclosing a ring of null intensity called the Poggendorff ring. We demonstrate both theoretically and experimentally that the Poggendorff dark ring of conical refraction is confined in three dimensions by regions of higher intensity. We derive the positions of the confining intensity maxima and minima and discuss the application of the Poggendorff ring for trapping ultra-cold atoms using the repulsive dipole force of blue-detuned light. We give analytical expressions for the trapping frequencies and potential depths along both the radial and the axial directions. Finally, we present realistic numerical simulations of the dynamics of a 87Rb Bose-Einstein condensate trapped inside the Poggendorff ring which are in good agreement with corresponding experimental results

Glial D-Serine Gates NMDA Receptors at Excitatory Synapses in Prefrontal Cortex.

N-methyl-D-aspartate receptors (NMDARs) subserve numerous neurophysiological and neuropathological processes in the cerebral cortex. Their activation requires the binding of glutamate and also of a coagonist. Whereas glycine and D-serine (D-ser) are candidates for such a role at central synapses, the nature of the coagonist in cerebral cortex remains unknown. We first show that the glycine-binding site of NMDARs is not saturated in acute slices preparations of medial prefrontal cortex (mPFC). Using enzymes that selectively degrade either D-ser or glycine, we demonstrate that under the present conditions, D-ser is the principle endogenous coagonist of synaptic NMDARs at mature excitatory synapses in layers V/VI of mPFC where it is essential for long-term potentiation (LTP) induction. Furthermore, blocking the activity of glia with the metabolic inhibitor, fluoroacetate, impairs NMDAR-mediated synaptic transmission and prevents LTP induction by reducing the extracellular levels of D-serine. Such deficits can be restored by exogenous D-ser, indicating that the D-amino acid mainly originates from glia in the mPFC, as further confirmed by double-immunostaining studies for D-ser and anti-glial fibrillary acidic protein. Our findings suggest that D-ser modulates neuronal networks in the cerebral cortex by gating the activity of NMDARs and that altering its levels is relevant to the induction and potentially treatment of psychiatric and neurological disorders

Molecular excitation in the Interstellar Medium: recent advances in collisional, radiative and chemical processes

We review the different excitation processes in the interstellar mediumComment: Accepted in Chem. Re

All-sky Search for High-Energy Neutrinos from Gravitational Wave Event GW170104 with the ANTARES Neutrino Telescope

Advanced LIGO detected a significant gravitational wave signal (GW170104) originating from the coalescence of two black holes during the second observation run on January 4$^{\textrm{th}}$, 2017. An all-sky high-energy neutrino follow-up search has been made using data from the ANTARES neutrino telescope, including both upgoing and downgoing events in two separate analyses. No neutrino candidates were found within $\pm500$ s around the GW event time nor any time clustering of events over an extended time window of $\pm3$ months. The non-detection is used to constrain isotropic-equivalent high-energy neutrino emission from GW170104 to less than $\sim4\times 10^{54}$ erg for a $E^{-2}$ spectrum

The ANTARES Collaboration: Contributions to ICRC 2017 Part I: Neutrino astronomy (diffuse fluxes and point sources)

Papers on neutrino astronomy (diffuse fluxes and point sources, prepared for the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the ANTARES Collaboratio

The ANTARES Collaboration: Contributions to ICRC 2017 Part III: Searches for dark matter and exotics, neutrino oscillations and detector calibration

Papers on the searches for dark matter and exotics, neutrino oscillations and detector calibration, prepared for the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the ANTARES Collaboratio