390 research outputs found
"Plantar pro gasto": a importĂąncia do autoconsumo entre famĂlias de agricultores do Rio Grande do Sul.
O artigo discute a valoração e importĂąncia da produção para o autoconsumo na reprodução social das unidades familiares e caracteriza os alimentos autoconsumidos. Vale-se da pesquisa "Agricultura Familiar, Desenvolvimento Local e Pluriatividade" (UFRGS/UFPel/ CNPq-2003) que propiciou a formação de um banco de dados com informaçÔes sobre a dinĂąmica da agricultura familiar em quatro regiĂ”es distintas da geografia gaĂșcha, suas fontes e tipos de renda, entre estas o autoconsumo. Trazer este debate significa retomar um tema pouco discutido atĂ© entĂŁo, e que, embora marginalizado ou considerado sem importĂąncia, desenvolve importante papel como renda nĂŁo monetĂĄria, fortalece a segurança alimentar e adentra esferas da sociabilidade e identidade social. AlĂ©m da introdução, apresenta-se o papel do autoconsumo na agricultura familiar, o cĂĄlculo da produção para o autoconsumo, discussĂŁo dos objetivos e resultados, e consideraçÔes finais. Os resultados demonstram que a produção para o autoconsumo Ă© uma estratĂ©gia recorrente pelas unidades familiares e se diferencia de acordo com a dinĂąmica da agricultura familiar. Diferença esta expressa em valores relativos (%) e no nĂșmero de estabelecimentos pertencentes a estratos diferenciados de autoconsumo, e pouco nos tipos de alimentos produzidos para este fim, observando-se uma homogeneidade dos hĂĄbitos alimentares
Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA
Deep-inelastic positron-proton interactions at low values of Bjorken-x down
to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons
are studied with the H1 experiment at HERA. The inclusive cross section for
pi^0 mesons produced at small angles with respect to the proton remnant (the
forward region) is presented as a function of the transverse momentum and
energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x.
Measurements are also presented of the transverse energy flow in events
containing a forward pi^0 meson. Hadronic final state calculations based on QCD
models implementing different parton evolution schemes are confronted with the
data.Comment: 27 pages, 8 figures and 3 table
Limb Spicules from the Ground and from Space
We amassed statistics for quiet-sun chromosphere spicules at the limb using
ground-based observations from the Swedish 1-m Solar Telescope on La Palma and
simultaneously from NASA's Transition Region and Coronal Explorer (TRACE)
spacecraft. The observations were obtained in July 2006. With the 0.2 arcsecond
resolution obtained after maximizing the ground-based resolution with the
Multi-Object Multi-Frame Blind Deconvolution (MOMFBD) program, we obtained
specific statistics for sizes and motions of over two dozen individual
spicules, based on movies compiled at 50-second cadence for the series of five
wavelengths observed in a very narrow band at H-alpha, on-band and in the red
and blue wings at 0.035 nm and 0.070 nm (10 s at each wavelength) using the
SOUP filter, and had simultaneous observations in the 160 nm EUV continuum from
TRACE. The MOMFBD restoration also automatically aligned the images,
facilitating the making of Dopplergrams at each off-band pair. We studied 40
H-alpha spicules, and 14 EUV spicules that overlapped H-alpha spicules; we
found that their dynamical and morphological properties fit into the framework
of several previous studies. From a preliminary comparison with spicule
theories, our observations are consistent with a reconnection mechanism for
spicule generation, and with UV spicules being a sheath region surrounding the
H-alpha spicules
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Water Vapor Vertical Profiles on Mars in Dust Storms Observed by TGO/NOMAD
It has been suggested that dust storms efficiently transport water vapor from the nearâsurface to the middle atmosphere on Mars. Knowledge of the water vapor vertical profile during dust storms is important to understand water escape. During Martian Year 34, two dust storms occurred on Mars: a global dust storm (June to midâSeptember 2018) and a regional storm (January 2019). Here we present water vapor vertical profiles in the periods of the two dust storms (Ls = 162â260° and Ls = 298â345°) from the solar occultation measurements by Nadir and Occultation for Mars Discovery (NOMAD) onboard ExoMars Trace Gas Orbiter (TGO). We show a significant increase of water vapor abundance in the middle atmosphere (40â100 km) during the global dust storm. The water enhancement rapidly occurs following the onset of the storm (Ls~190°) and has a peak at the most active period (Ls~200°). Water vapor reaches very high altitudes (up to 100 km) with a volume mixing ratio of ~50 ppm. The water vapor abundance in the middle atmosphere shows high values consistently at 60°Sâ60°N at the growth phase of the dust storm (Ls = 195°â220°), and peaks at latitudes greater than 60°S at the decay phase (Ls = 220°â260°). This is explained by the seasonal change of meridional circulation: from equinoctial Hadley circulation (two cells) to the solstitial one (a single poleâtoâpole cell). We also find a conspicuous increase of water vapor density in the middle atmosphere at the period of the regional dust storm (Ls = 322â327°), in particular at latitudes greater than 60°S
A new class of Roche lobeâfilling hot subdwarf binaries
We present the discovery of the second binary with a Roche lobeâfilling hot subdwarf transferring mass to a white dwarf (WD) companion. This 56 minute binary was discovered using data from the Zwicky Transient Facility. Spectroscopic observations reveal an He-sdOB star with an effective temperature of T eff = 33,700 ± 1000 K and a surface gravity of log(g) = 5.54 ± 0.11. The GTC+HiPERCAM light curve is dominated by the ellipsoidal deformation of the He-sdOB star and shows an eclipse of the He-sdOB by an accretion disk as well as a weak eclipse of the WD. We infer a He-sdOB mass of M sdOB = 0.41 ± 0.04 M â and a WD mass of M WD = 0.68 ± 0.05 M â. The weak eclipses imply a WD blackbody temperature of 63,000 ± 10,000 K and a radius R WD = 0.0148 ± 0.0020 R â as expected for a WD of such high temperature. The He-sdOB star is likely undergoing hydrogen shell burning and will continue transferring mass for â1 Myr at a rate of 10â9 M â yrâ1, which is consistent with the high WD temperature. The hot subdwarf will then turn into a WD and the system will merge in â30 Myr. We suggest that Galactic reddening could bias discoveries toward preferentially finding Roche lobeâfilling systems during the short-lived shell-burning phase. Studies using reddening-corrected samples should reveal a large population of helium coreâburning hot subdwarfs with T eff â 25,000 K in binaries of 60â90 minutes with WDs. Though not yet in contact, these binaries would eventually come into contact through gravitational-wave emission and explode as a subluminous thermonuclear supernova or evolve into a massive single WD
Inelastic photoproduction of J/Psi mesons at HERA
An analysis of inelastic photoproduction of J/Psi mesons is presented using data collected at the ep collider HERA corresponding to an integrated luminosity of above 80pb-1. Differential and double differential cross sections are measured in a wide kinematic region: 6
Comprehensive analysis of epigenetic clocks reveals associations between disproportionate biological ageing and hippocampal volume
The concept of age acceleration, the difference between biological age and chronological age, is of growing interest, particularly with respect to age-related disorders, such as Alzheimerâs Disease (AD). Whilst studies have reported associations with AD risk and related phenotypes, there remains a lack of consensus on these associations. Here we aimed to comprehensively investigate the relationship between five recognised measures of age acceleration, based on DNA methylation patterns (DNAm age), and cross-sectional and longitudinal cognition and AD-related neuroimaging phenotypes (volumetric MRI and Amyloid-ÎČ PET) in the Australian Imaging, Biomarkers and Lifestyle (AIBL) and the Alzheimerâs Disease Neuroimaging Initiative (ADNI). Significant associations were observed between age acceleration using the Hannum epigenetic clock and cross-sectional hippocampal volume in AIBL and replicated in ADNI. In AIBL, several other findings were observed cross-sectionally, including a significant association between hippocampal volume and the Hannum and Phenoage epigenetic clocks. Further, significant associations were also observed between hippocampal volume and the Zhang and Phenoage epigenetic clocks within Amyloid-ÎČ positive individuals. However, these were not validated within the ADNI cohort. No associations between age acceleration and other Alzheimerâs disease-related phenotypes, including measures of cognition or brain Amyloid-ÎČ burden, were observed, and there was no association with longitudinal change in any phenotype. This study presents a link between age acceleration, as determined using DNA methylation, and hippocampal volume that was statistically significant across two highly characterised cohorts. The results presented in this study contribute to a growing literature that supports the role of epigenetic modifications in ageing and AD-related phenotypes
Measurement of CP observables in B± â D(â)K± and B± â D(â)ϱ decays
Measurements of CP observables in B ± âD (â) K ± and B ± âD (â) Ï Â± decays are presented, where D (â) indicates a neutral D or D â meson that is an admixture of D (â)0 and DÂŻ (â)0 states. Decays of the D â meson to the DÏ 0 and DÎł final states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the B candidate invariant mass distribution. Decays of the D meson are fully reconstructed in the K ± Ï â , K + K â and Ï + Ï â final states. The analysis uses a sample of charged B mesons produced in pp collisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0 fb â1 taken at centre-of-mass energies of s=7, 8 and 13 TeV, respectively. The study of B ± âD â K ± and B ± âD â Ï Â± decays using a partial reconstruction method is the first of its kind, while the measurement of B ± âDK ± and B ± âDÏ Â± decays is an update of previous LHCb measurements. The B ± âDK ± results are the most precise to date
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