Electronic state spectroscopy of C₂Cl₄

The VUV spectrum of C2Cl4 is reported in the energy range 3.8-10.8 eV (325-115 nm). Several photoabsorption features are observed for the first time, including a very weak low-lying band which is provisionally attributed to a π → π* triplet transition. Recent ab initio calculations of the molecule’s electronic transitions [Arulmozhiraja et al. J. Chem. Phys. 129 (2008) 174506] provide the basis for the present assignments below 8.5 eV. An extended ndπ series is proposed to account for several higher-energy Rydberg bands. The identification of vibrational structure, dominated by symmetric C=C and CCl2 stretching in excitations from the HOMO, largely agrees with previous spectroscopic studies. The present absolute photoabsorption cross sections cover a wider energy range than the previous measurements and are used to calculate UV photolysis lifetimes of this aeronomic molecule at altitudes between 20 and 50 km

The chiral Anomalous Hall effect in re-entrant AuFe alloys

The Hall effect has been studied in a series of AuFe samples in the re-entrant concentration range, as well as in part of the spin glass range. An anomalous Hall contribution linked to the tilting of the local spins can be identified, confirming theoretical predictions of a novel topological Hall term induced when chirality is present. This effect can be understood in terms of Aharonov-Bohm-like intrinsic current loops arising from successive scatterings by canted local spins. The experimental measurements indicate that the chiral signal persists, meaning scattering within the nanoscopic loops remains coherent, up to temperatures of the order of 150 K.Comment: 7 pages, 11 eps figures Published version. Minor change

Submillimetre galaxies reside in dark matter haloes with masses greater than 3 × 10^(11) solar masses

The extragalactic background light at far-infrared wavelengths comes from optically faint, dusty, star-forming galaxies in the Universe with star formation rates of a few hundred solar masses per year. These faint, submillimetre galaxies are challenging to study individually because of the relatively poor spatial resolution of far-infrared telescopes. Instead, their average properties can be studied using statistics such as the angular power spectrum of the background intensity variations. A previous attempt at measuring this power spectrum resulted in the suggestion that the clustering amplitude is below the level computed with a simple ansatz based on a halo model. Here we report excess clustering over the linear prediction at arcminute angular scales in the power spectrum of brightness fluctuations at 250, 350 and 500 µm. From this excess, we find that submillimetre galaxies are located in darkmatter haloes with a minimum mass, M_(min), such that log_(10)[M_(min)/M_⊙] = 11.5^(+0.7)_(-0.2) at 350 µm, where M_⊙ is the solar mass. This minimum dark matter halo mass corresponds to the most efficient mass scale for star formation in the Universe, and is lower than that predicted by semi-analytical models for galaxy formation

Monensina sódica no controle da eimeriose em caprinos leiteiros.

A eficácia de drogas para o controle da eimeriose caprina é limitada quando já há sintomas clínicos, sendo o tratamento preventivo mais eficaz que o curativo. Desta forma, foi avaliado o uso da monensina no controle da eimeriose em caprinos leiteiros. Foram utilizadas 48 fêmeas, 32 da raça Anglo-nubiana e 16 da raça Saanen, com idade entre três e quatro meses, distribuídas aleatoriamente por sorteio em dois tratamentos. O tratamento I, constituído por 24 animais, sendo 16 Anglo-nubiana e oito Saanen, não foram medicadas (controle) e o tratamento II, formado por 24 animais, 16 Anglo-nubiana e oito Saanen, foram medicadas diariamente com 0,5mg/kg de monensina durante 234 dias. O número médio de oocistos por grama de fezes (OOPG) durante todo o experimento do grupo controle foi superior ao do grupo medicado (P0,05) na média geral de OOPG entre as duas raças. O padrão da curva de OOPG dos animais da raça Anglo-nubiana diferiu entre os tratamentos (P0,05) na média geral de peso entre os dois tratamentos, entretanto, o peso desta raça foi superior (P0,05) na curva de ganho de peso entre os dois tratamentos, para as duas raças, entretanto, os animais da raça Saanen ganharam mais peso do que os animais da raça Anglo-nubiana (63g/dia vs. 41g/dia). [Sodium monensin for eimeriosis control in dairy goat herd]. Abstract - The efficacy of drugs to control caprine eimeriosis is limited when clinical symptoms already exist, and preventive treatment is more efficient than cure. Thus, the use of sodium monensin was evaluated in order to control caprine eimeriosis in dairy goats. 48 females, 32 Anglo-Nubian and 16 Saanen, aged between three and four months, were randomly distributed in two treatments. Treatment I had 24 animals, being 16 Anglo-Nubian and eight Saanen, which did not receive any medication (control); Treatment II, which was composed of 24 animals (16 Anglo-Nubian and eight Saanen), were medicated daily with a 0.5 mg/kg of body weight dose of monensin for 234 days. The average number of oocytes per gram of feces (OOPG) in the control group in the whole period was higher than the medicated group. There was no statistical difference (P>0.05) in the general average between the two breeds. The standard curve of OOPG from Anglo-Nubian animals differed between treatments (P0.05) in the general average weight between both treatments. However, the average live weight in this breed was superior (P0.05) in the curve of weight gain between treatments, in both breeds; nevertheless, the Saanen animals presented higher weight gain (P<0.05) than the Anglo-Nubian animals (63 g/day vs. 41 g/day)

Efeito da temperatura e fotoperíodo na esporulação de Trichoderma em meio líquido.

Resumo: Trichoderma é um dos agentes de controle biológico de doenças mais utilizados na agricultura, cuja produção de esporos é realizada industrialmente em meio sólido, pois sua esporulação em meio liquido é ainda um desafio. Neste contexto, a definição dos parâmetros capazes de promover maior produção de esporos em fermentação líquida vem sendo investigada. Portanto, o objetivo deste trabalho é estabelecer uma temperatura e fotoperíodo que sejam ótimos para obter maior produção de esporos com boa viabilidade. No ensaio utilizou-se um isolado de Trichoderma asperellum que foi cultivado em meio Czapek-Dox e sacarose como fonte de carbono com temperaturas de 15, 25 e 30ºC entre fotoperíodos 0, 12 e 24 horas, sendo o arranjo fatorial 3x3. Um disco de micélio de T. asperellum foi colocado em frascos de 250ml onde permaneceram por um período de 7 dias em um agitador orbital. Para as avaliações foram quantificadas as concentrações de esporos, percentual de conídios viáveis, unidades formadoras de colônias e massa seca. As análises foram realizadas por meio de análise de variância e teste de Tukey a 5%. A temperatura de 30ºC foi a melhor utilizada, independente do fotoperíodo. A temperatura de 25ºC apresentou resultados significativamente similares a 30ºC, exceto para a concentração de conídios, que foi menor. Para o teste de germinação os fatores avaliados não interferiram no ensaio. Abstract: Thichoderma is one of the most widely used biocontrol agents in agriculture, whose spore production is manufactured in solid media, because its sporulation in liquid media is still a challenge. In this context, the definition of parameters which are able to promote wider yield of spores in liquid fermentation has been investigated. Therefore, the objective of this work is to establish an ideal temperature and photoperiod to produce spores with good viability. In treatments, a Trichoderma asperellum isolate cultivated in Czapek-Dox media and sucrose as a source of carbon with temperatures of 15, 25 and 30oC among photoperiods of 0, 12 and 24 hours being the factorial arrangement of 3x3 was used. A mycelium disk of T. asperellum was placed in the 250ml flasks where remained for a period of seven days on an orbital shaker. For the evaluation were quantified the spore concentrations, viable conidial percentage, colony forming units and dry weight. The analyzes were performed by analysis of variance and Tykey test at 5%. The temperature of 30oC was the best utilized, regardless of photoperiod. The temperature of 25oC was significantly similar to 30oC, except for the concentration of conidia, that was lower. For the germination test the evaluated factors do not interfere in the experiment

Superconductivity and magnetism on flux grown single crystals of NiBi3

We present resistivity, magnetization and specific heat measurements on flux grown single crystals of NiBi3. We find typical behavior of a type-II superconductor, with, however, a sizable magnetic signal in the superconducting phase. There is a hysteretic magnetization characteristic of a ferromagnetic compound. By following the magnetization as a function of temperature, we find a drop at temperatures corresponding to the Curie temperature of ferromagnetic amorphous Ni. Thus, we assign the magnetism in NiBi$_3$ crystals to amorphous Ni impurities

From Scattering Amplitudes to the Dilatation Generator in N=4 SYM

The complete spin chain representation of the planar N=4 SYM dilatation generator has long been known at one loop, where it involves leading nearest-neighbor 2 -> 2 interactions. In this work we use superconformal symmetry to derive the unique solution for the leading L -> 2 interactions of the planar dilatation generator for arbitrarily large L. We then propose that these interactions are given by the scattering operator that has N=4 SYM tree-level scattering amplitudes as matrix elements. We provide compelling evidence for this proposal, including explicit checks for L=2,3 and a proof of consistency with superconformal symmetry.Comment: 39 pages, v2: reference added and minor changes, published versio

Mancha-bacteriana do maracujazeiro (Xanthomonas axonopodis pv. passiflorae): etiologia e estratégias de controle.

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