Padrões tecnológicos e econômicos do arroz de terras altas.

O presente trabalho teve como objetivo atualizar as informações sobre a cultura do arroz no Mato Grosso, visando fornecer subsídios às ações de pesquisa e transferência de tecnologia.bitstream/CNPAF/20437/1/comt_52.pd

Lamb Production Costs: Analyses of Composition and Elasticities Analysis of Lamb Production Costs

Since lamb is a commodity, producers cannot control the price of the product they sell. Therefore, managing production costs is a necessity. We explored the study of elasticities as a tool for basing decision-making in sheep production, and aimed at investigating the composition and elasticities of lamb production costs, and their influence on the performance of the activity. A representative sheep production farm, designed in a panel meeting, was the base for calculation of lamb production cost. We then performed studies of: i) costs composition, and ii) cost elasticities for prices of inputs and for zootechnical indicators. Variable costs represented 64.15% of total cost, while 21.66% were represented by operational fixed costs, and 14.19% by the income of the factors. As for elasticities to input prices, the opportunity cost of land was the item to which production cost was more sensitive: a 1% increase in its price would cause a 0.2666% increase in lamb cost. Meanwhile, the impact of increasing any technical indicator was significantly higher than the impact of rising input prices. A 1% increase in weight at slaughter, for example, would reduce total cost in 0.91%. The greatest obstacle to economic viability of sheep production under the observed conditions is low technical efficiency. Increased production costs are more related to deficient zootechnical indexes than to high expenses

Interpretation of the Veiling of the Photospheric Spectrum for T Tauri Stars in Terms of an Accretion Model

The problem on heating the atmospheres of T Tauri stars by radiation from an accretion shock has been solved. The structure and radiation spectrum of the emerging so-called hot spot have been calculated in the LTE approximation. The emission not only in continuum but also in lines has been taken into account for the first time when calculating the spot spectrum. Comparison with observations has shown that the strongest of these lines manifest themselves as narrow components of helium and metal emission lines, while the weaker ones decrease significantly the depth of photospheric absorption lines, although until now, this effect has been thought to be due to the emission continuum alone. The veiling by lines changes the depth of different photospheric lines to a very different degree even within a narrow spectral range. Therefore, the nonmonotonic wavelength dependence of the degree of veiling r found for some CTTS does not suggest a nontrivial spectral energy distribution of the veiling continuum. In general, it makes sense to specify the degree of veiling r only by providing the set of photospheric lines from which this quantity was determined. We show that taking into account the contribution of lines to the veiling of the photospheric spectrum can cause the existing estimates of the accretion rate onto T Tauri stars to decrease by several times, with this being also true for stars with a comparatively weakly veiled spectrum. Neglecting the contribution of lines to the veiling can also lead to appreciable errors in determining the effective temperature, interstellar extinction, radial velocity, and vsin(i)

How can nutritional strategies and feed technologies in pig production affect the logistical costs of manure distribution?

The objective with this study was to evaluate the impact of different swine nutritional strategies and technologies, as well as the land spread system, on logistical costs of pig manure distribution. For this, pigs were fed a conventional diet (C0) or a diet supplemented with 0.01% phytase (C1); organic minerals (40% substitution; C2); synthetic amino acids at reduced dietary crude protein levels (C3); or a combination of the three strategies (C4). All pig manure was weighed, then its chemical composition was determined. The mineral values and volume of manure produced were extrapolated to corresponding pig farm sizes in Sao Paulo state (300, 650, and 1000 sows) from real pig manure levels to produce simulations. To determine the logistical cost of manure distribution, two distribution systems were considered: vacuum tank tractor and vacuum tank truck (4.30 and 15 m³, respectively). The land spread truck system had the highest cost/hour worked due to the higher fuel consumption. However, this cost might be different over greater distances. Manure production, as well as the nutrient levels of N, P, and K, were lower for swine fed diets supplemented with nutritional technologies. Therefore, the different nutritional technologies reduced the transportation and distribution cost of pig manure by reducing the area and, consequently, the distances that need to be traveled for distribution. However, from an agronomic point of view (i.e., to meet a crop fertilization demand per hectare), manure from pigs fed diets supplemented with nutritional technologies had a higher application rate on land

The persistence landscape and some of its properties

Persistence landscapes map persistence diagrams into a function space, which may often be taken to be a Banach space or even a Hilbert space. In the latter case, it is a feature map and there is an associated kernel. The main advantage of this summary is that it allows one to apply tools from statistics and machine learning. Furthermore, the mapping from persistence diagrams to persistence landscapes is stable and invertible. We introduce a weighted version of the persistence landscape and define a one-parameter family of Poisson-weighted persistence landscape kernels that may be useful for learning. We also demonstrate some additional properties of the persistence landscape. First, the persistence landscape may be viewed as a tropical rational function. Second, in many cases it is possible to exactly reconstruct all of the component persistence diagrams from an average persistence landscape. It follows that the persistence landscape kernel is characteristic for certain generic empirical measures. Finally, the persistence landscape distance may be arbitrarily small compared to the interleaving distance.Comment: 18 pages, to appear in the Proceedings of the 2018 Abel Symposiu

A search for pulsations in the HgMn star HD 45975 with CoRoT photometry and ground-based spectroscopy

The existence of pulsations in HgMn stars is still being debated. To provide the first unambiguous observational detection of pulsations in this class of chemically peculiar objects, the bright star HD 45975 was monitored for nearly two months by the CoRoT satellite. Independent analyses of the light curve provides evidence of monoperiodic variations with a frequency of 0.7572 c/d and a peak-to-peak amplitude of ~2800 ppm. Multisite, ground-based spectroscopic observations overlapping the CoRoT observations show the star to be a long-period, single-lined binary. Furthermore, with the notable exception of mercury, they reveal the same periodicity as in photometry in the line moments of chemical species exhibiting strong overabundances (e.g., Mn and Y). In contrast, lines of other elements do not show significant variations. As found in other HgMn stars, the pattern of variability consists in an absorption bump moving redwards across the line profiles. We argue that the photometric and spectroscopic changes are more consistent with an interpretation in terms of rotational modulation of spots at the stellar surface. In this framework, the existence of pulsations producing photometric variations above the ~50 ppm level is unlikely in HD 45975. This provides strong constraints on the excitation/damping of pulsation modes in this HgMn star.Comment: Accepted for publication in A&A, 14 pages, 15 colour figures (revised version after language editing

AzTEC 1.1 mm Observations of the MBM12 Molecular Cloud

We present 1.1 mm observations of the dust continuum emission from the MBM12 high-latitude molecular cloud observed with the Astronomical Thermal Emission Camera (AzTEC) mounted on the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. We surveyed a 6.34 deg$^2$ centered on MBM12, making this the largest area that has ever been surveyed in this region with submillimeter and millimeter telescopes. Eight secure individual sources were detected with a signal-to-noise ratio of over 4.4. These eight AzTEC sources can be considered to be real astronomical objects compared to the other candidates based on calculations of the false detection rate. The distribution of the detected 1.1 mm sources or compact 1.1 mm peaks is spatially anti-correlated with that of the 100 micronm emission and the $^{12}$CO emission. We detected the 1.1 mm dust continuum emitting sources associated with two classical T Tauri stars, LkHalpha262 and LkHalpha264. Observations of spectral energy distributions (SEDs) indicate that LkHalpha262 is likely to be Class II (pre-main-sequence star), but there are also indications that it could be a late Class I (protostar). A flared disk and a bipolar cavity in the models of Class I sources lead to more complicated SEDs. From the present AzTEC observations of the MBM12 region, it appears that other sources detected with AzTEC are likely to be extragalactic and located behind MBM12. Some of these have radio counterparts and their star formation rates are derived from a fit of the SEDs to the photometric evolution of galaxies in which the effects of a dusty interstellar medium have been included.Comment: 8 pages, 6 figures, The Astrophysical Journal, in pres

Coordinated Multiwavelength Observations of V410Tau

In November 2001 we undertook a coordinated observing campaign to study the connection between X-ray and optical variability in the weak-line T Tauri star V410Tau. The observing plan included three 15 ksec observations with Chandra using the Advanced CCD Imaging Spectrometer for Spectroscopy scheduled for different phases of the known 1.87 d starspot cycle. Photometric and spectroscopic monitoring of V410Tau involving telescopes on three different continents was scheduled simultaneously with the Chandra exposures.Comment: 3 pages, Poster Proceedings of "1st Potsdam Thinkshop on Sunspots and Starspots", Potsdam, Germany, May 200