Detection of Ionospheric Alfven Resonator Signatures Onboard C/NOFS: Implications for IRI Modeling

The 2008-2009 long-lasting solar minimum activity has been the one of its kind since the dawn of space age, offering exceptional conditions for investigating space weather in the near-Earth environment. First ever detection of Ionospheric Alfven Resonator (IAR) signatures in orbit offers new means for investigating ionospheric electrodynamics, namely MHD (MagnetoHydroDynamics) wave propagation, aeronomy processes, ionospheric dynamics, and Sun-Earth connection mechanisms at a local scale. Local and global plasma density heterogeneities in the ionosphere and magnetosphere allow for formation of waveguides and resonators where magnetosonic and shear Alfven waves propagate. The ionospheric magnetosonic waveguide results from complete magnetosonic wave reflection about the ionospheric F-region peak, where the Alfven index of refraction presents a maximum. MHD waves can also be partially trapped in the vertical direction between the lower boundary of the ionosphere and the magnetosphere, a resonance mechanism known as IAR. In this work we present C/NOFS (Communications/Navigation Outage Forecasting System) Extremely Low Frequency (ELF) electric field measurements related to IAR signatures, discuss the resonance and wave propagation mechanisms in the ionosphere, and address the electromagnetic inverse problem from which electron/ion distributions can be derived. These peculiar IAR electric field measurements provide new, complementary methodologies for inferring ionospheric electron and ion density profiles, and also contribute for the investigation of ionosphere dynamics and space weather monitoring. Specifically, IAR spectral signatures measured by C/NOFS contribute for improving the International Reference Ionosphere (IRI) model, namely electron density and ion composition

A Topside Equatorial Ionospheric Density and Composition Climatology During and After Extreme Solar Minimum

During the recent solar minimum, solar activity reached the lowest levels observed during the space age. This extremely low solar activity has accompanied a number of unexpected observations in the Earth's ionosphere and thermosphere when compared to previous solar minima. Among these are the fact that the ionosphere is significantly contracted beyond expectations based on empirical models. Climatological altitude profiles of ion density and composition measurements near the magnetic dip equator are constructed from the C/NOFS satellite to characterize the shape of the top side ionosphere during the recent solar minimum and into the new solar cycle. The variation of the profiles with respect to local time, season, and solar activity are compared to the IRI-2007 model. Building on initial results reported by Heelis et al. [2009], here we describe the extent of the contracted ionosphere, which is found to persist throughout 2009. The shape of the ionosphere during 2010 is found to be consistent with observations from previous solar minima

Performance of the IRI-2007 Model for Topside Ion Density and Composition Profiles During the 23/24 Solar Minimum

The recent solar minimum between cycles 23 and 24 was unusually extended and deep, resulting in an ionosphere that is significantly different from that expected based on previous solar minima. The ion density and composition estimates from the Communication/Navigation Outage Forecast System (C/NOFS) satellite are used to evaluate the performance of the IRI-2007 model between 400 and 850 kIn altitude in equatorial regions. The current model is shown to typically overestimate the expected topside density of 0+ and underestimate the density of H+ during 2008 and 2009. The overestimation of ion density by IRI-2007 is found to vary with local time and longitude

Evolution of the eyes of vipers with and without infrared-sensing pit organs

We examined lens and brille transmittance, photoreceptors, visual pigments, and visual opsin gene sequences of viperid snakes with and without infrared-sensing pit organs. Ocular media transmittance is high in both groups. Contrary to previous reports, small as well as large single cones occur in pit vipers. Non-pit vipers differ from pit vipers in having a twotiered retina, but few taxa have been examined for this poorly understood feature. All vipers sampled express rh1, sws1 and lws visual opsin genes. Opsin spectral tuning varies but not in accordance with the presence/absence of pit organs, and not always as predicted from gene sequences. The visual opsin genes were generally under purifying selection, with positive selection at spectral tuning amino acids in RH1 and SWS1 opsins, and at retinal pocket stabilization sites in RH1 or LWS (and without substantial differences between pit and nonpit vipers). Lack of evidence for sensory trade-off between viperid eyes (in the aspects examined) and pit organs might be explained by the high degree of neural integration of vision and infrared detection; the latter representing an elaboration of an existing sense with addition of a novel sense organ, rather than involving the evolution of a wholly novel sensory system

Repercussions of growth path on carcass characteristics, meat colour and shear force in Alentejana bulls

The aim of this study was to evaluate the carcass and meat characteristics of eight muscles from bulls with distinct growth paths. A total of 40 Alentejana male calves were allocated to two distinct feeding regimes. In the continuous growth (CG) system, the animals were fed concentrates plus hay and were slaughtered at 18 months of age. On the other hand, in the discontinuous growth (DG) system, the animals were fed hay until 15 months of age; the cattle were then fed the same diet provided to the CG group from 15 to 24 months of age. The DG reduced hot carcass weight, fatness and dressing %, but the proportions of fat, bone and muscle tissues in the leg were not affected. In contrast, there was a positive impact of compensatory growth on supraspinatus, triceps brachii, semitendinosus, biceps femoris muscle tenderness, overcoming the negative effects of age at slaughter. The reasons for such improvement in meat tenderness were not related to intra-muscular fat content or myofibrillar protein degradation values. An association between tenderness and muscle collagen properties was not established. The results indicate that the compensatory growth has a muscle-dependent effect

Physical and Quality Seed Traits Observed in New Pigeon Pea (\u3cem\u3eCajanus Cajan\u3c/em\u3e) Hybrids

Pigeon pea seed production may be affected by factors such as % of pure seeds, mean seed weight, incidence of pests and diseases and environmental stresses. Harvested seeds from different cultivars may also vary in germination %, hardseededness and germination speed. Hardseededness (seed coat impermeability to water) commonly occurs in forage legume species (Hopkinson, 1993). There is considerable variation among different entries for seed characters but this is not considered within genetic materials. This research analysed harvested seeds of selected individuals of two segregating F2 pigeon pea populations for the above cited traits and assessed the range of variation for them resulting from the hybridisation process

Morphological responses, fruit yield, nutritive value and in vitro gas production of forage watermelon genotypes on semi-arid condition.

This study aimed to evaluate morphological, bromatological, in vitro gas production and yield of forage watermelon (Citrullus lanatus var. citroides) genotypes in semi-arid condition. Seven genotypes were evaluated were BGCIA 228, BGCIA 239, Jojoba, BGCIA 228 x BGCIA239, BGCIA 228 x BGCIA Jojoba, BGCIA 239 x Jojoba and BGCIA 991. The experimental design was a complete randomized block with three replicates. The genotypes presented differences between the characteristics: fruit length (P = 0.01), vertical diameter (P = 0.02), peel thickness (P = 0.01), fruit pulp thickness (P = 0.02), transversal diameter (P = 0.02), in vitro dry matter digestibility (P = 0.003) and the latency time (P < 0.0001). Cumulative in vitro gas production and gas production rate was not affected by genotypes. None of the studied genotypes had production and productivity affected. Among them, Jojoba and BGCIA 991 stood out for having heavier and longer fruits, and a higher peel thickness and pulp length

Análise biométrica de cultivares de cana-de-açúcar inoculadas com bactérias fixadoras de nitrogênio.

Este trabalho objetivou avaliar as características de crescimento de cultivares de cana-de-açúcar inoculadas com bactérias fixadoras de nitrogênio, em condição irrigada no Semiárido. O estudo foi desenvolvido na Usina Agrovale em delineamento de blocos casualizados, sendo os tratamentos representados por seis cultivares de cana-de-açúcar: RB 867515, RB 72454, RB 961003, RB 92579, PX 0178 e PX 01306, cultivadas com e sem inoculação e por dois tratamentos de RB 867515 e RB 72454 adubadas com 120 kg de N ha-1. As avaliações biométricas consistiram na contagem de perfilhos aos 30, 60 e 90 dias após o plantio (DAP), e na avaliação da altura, do diâmetro do colmo e do número de colmos aos 5 e 9 meses após o plantio. Em relação ao número de perfilhos, aos 90 DAP, observou-se que não houve diferenças entre os tratamentos. O número de colmos aumentou em relação aos resultados da primeira avaliação, mas não houve diferenças entre os tratamentos. As parcelas que receberam 120 kg de N ha-1 foram incluídas no grupo de menor diâmetro dos colmos. A altura da maioria das cultivares inoculadas se igualou à altura das plantas que foram fertilizadas com 120 kg de N ha-1

Performance of the IRI-2007 and SAMI2 Models during Extreme Solar Minimum

During the recent solar minimum, solar activity reached the lowest levels observed during the space age. This extremely low solar activity has accompanied a number of unexpected observations in the Earth's ionosphere and thermosphere when compared to previous solar minima. Among these is the fact that the ionosphere is significantly contracted beyond expectations based on empirical models. Data from the CINDI instrument on board C/NOFS is used to evaluate the performance of the IRI-2007 and SAMI2 models during the deepest part of the minimum. Additionally, the inputs to SAMI2 are modified in order to estimate the contributions of a contracted thermosphere and reduced EUV on the resultant ionosphere