Dinâmica da vegetação em pastagem nativa, submetida a diferentes métodos de controle de espécies indesejáveis e adubaçãoVegetation dynamics in native pasture submitted to control methods for weeds species and fertilization

Em área de pastagem nativa representativa da transição entre a Serra do Sudeste e a Depressão Central do Rio Grande do Sul, foram testados os efeitos associativos de quatro métodos de controle de plantas indesejáveis 1 - sem controle (SC); 2 - controle mecânico - roçada de primavera (CMP); 3 - controle mecânico - roçada de outono (CMO) e 4 - controle químico - herbicida comercial a base de Picloram (64 g.l-1) + 2,4-D (240 g.l-1), na dosagem de 5 l p.c.ha-1 (CQT)), dois sistemas de fertilização (1 - sem-adubo e 2 - com adubo), duas datas de avaliação (1 - primeira data - 16/05/2003 e 2 - segunda data - 26/03/2004 ) e dois toques na pastagem (1 - estrato superior e 2 - estrato inferior) sobre a composição florística e freqüência de espécies. As leguminosas nativas ocupam, com maior frequência, o estrato inferior da pastagem (5,9%), as indesejáveis, ao contrário das leguminosas, ocupam o estrato superior (5%). O controle químico proporcionou aumento na frequência de gramíneas à medida que diminuiu a participação de leguminosas. A gramínea com maior participação na composição da pastagem foi o Paspalum notatum com diminuição especialmente de Desmodium incanum dentre as leguminosas no CQT. A adubação favoreceu a participação da leguminosa Trifolium polymorphum (2,0% vs 1,1%, com adubação e sem-adubação, respectivamente). O controle mecânico proporcionou aumento na frequência de Vernonia nudiflora no estrato inferior (5,7%) da pastagem comparando-se ao SC (3,6%). O controle mecânico de outono, com apenas uma roçada durante o período experimental, foi mais eficiente que o mecânico de primavera.Abstract In a representative natural pasture area in the transition between the Serra do Sudeste and Depressão Central in Rio Grande do Sul, the associated effects of four methods for controlling undesirable species were tested (1 = without control (SC), 2 = mechanical control – spring mowing (CMP), 3 = mechanical control – autumn mowing (CMO) and 4 = chemical control – commercial herbicide Tordon, composed by Picloram (64 g.l-1) + 2,4-D (240 g.l-1), in the dosage of 5 l p.c.ha-1 (CQT)), associated to two systems of fertilization ( 1 = without fertilizer and 2 = with fertilizer). Two evaluation times (05/16/03 and 03/26/04) and two touch in pasture (1 = first touch and 2 = second touch) were considered on aspects related to the floristic survey and species frequency. The native leguminous plants generally appear in the lower stratus of the pasture (5.9 %), the undesirable ones appear in the upper stratus (5.0%). The chemical control promoted an increase in the grass frequency, as well as decreased the leguminous presence. The Paspalum notatum is the most frequent grass, and Desmodium incanum, mainly, decreased (among the legumes) in CQT. The fertilization favored the Trifolium polymorphum participation (2.0% vs 1.1% with and without fertilization, respectively). The mechanical control increased the frequency of Vernonia nudiflora in lower pasture stratus (5.7%) comparing to SC (3.6%). The autumn mechanical control with only one application during the experience time was more effi cient than the spring mechanical control

SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems

Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. In keeping with SDSS tradition, SDSS-III will provide regular public releases of all its data, beginning with SDSS DR8 (which occurred in Jan 2011). This paper presents an overview of the four SDSS-III surveys. BOSS will measure redshifts of 1.5 million massive galaxies and Lya forest spectra of 150,000 quasars, using the BAO feature of large scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z<0.7 and at z~2.5. SEGUE-2, which is now completed, measured medium-resolution (R=1800) optical spectra of 118,000 stars in a variety of target categories, probing chemical evolution, stellar kinematics and substructure, and the mass profile of the dark matter halo from the solar neighborhood to distances of 100 kpc. APOGEE will obtain high-resolution (R~30,000), high signal-to-noise (S/N>100 per resolution element), H-band (1.51-1.70 micron) spectra of 10^5 evolved, late-type stars, measuring separate abundances for ~15 elements per star and creating the first high-precision spectroscopic survey of all Galactic stellar populations (bulge, bar, disks, halo) with a uniform set of stellar tracers and spectral diagnostics. MARVELS will monitor radial velocities of more than 8000 FGK stars with the sensitivity and cadence (10-40 m/s, ~24 visits per star) needed to detect giant planets with periods up to two years, providing an unprecedented data set for understanding the formation and dynamical evolution of giant planet systems. (Abridged)Comment: Revised to version published in The Astronomical Journa

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure &lt;= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Vegetation dynamics in native pasture submitted to control methods for weeds species and fertilization

Em área de pastagem nativa representativa da transição entre a Serra do Sudeste e a Depressão Central do Rio Grande do Sul, foram testados os efeitos associativos de quatro métodos de controle de plantas indesejáveis 1 - sem controle (SC); 2 - controle mecânico - roçada de primavera (CMP); 3 - controle mecânico - roçada de outono (CMO) e 4 - controle químico - herbicida comercial a base de Picloram (64 g.l-1) + 2,4-D (240 g.l-1), na dosagem de 5 l p.c.ha-1 (CQT)), dois sistemas de fertilização (1 - sem-adubo e 2 - com adubo), duas datas de avaliação (1 - primeira data - 16/05/2003 e 2 - segunda data - 26/03/2004 ) e dois toques na pastagem (1 - estrato superior e 2 - estrato inferior) sobre a composição florística e freqüência de espécies. As leguminosas nativas ocupam, com maior frequência, o estrato inferior da pastagem (5,9%), as indesejáveis, ao contrário das leguminosas, ocupam o estrato superior (5%). O controle químico proporcionou aumento na frequência de gramíneas à medida que diminuiu a participação de leguminosas. A gramínea com maior participação na composição da pastagem foi o Paspalum notatum com diminuição especialmente de Desmodium incanum dentre as leguminosas no CQT. A adubação favoreceu a participação da leguminosa Trifolium polymorphum (2,0% vs 1,1%, com adubação e sem-adubação, respectivamente). O controle mecânico proporcionou aumento na frequência de Vernonia nudiflora no estrato inferior (5,7%) da pastagem comparando-se ao SC (3,6%). O controle mecânico de outono, com apenas uma roçada durante o período experimental, foi mais eficiente que o mecânico de primavera.In a representative natural pasture area in the transition between the Serra do Sudeste and Depressão Central in Rio Grande do Sul, the associated effects of four methods for controlling undesirable species were tested (1 = without control (SC), 2 = mechanical control – spring mowing (CMP), 3 = mechanical control – autumn mowing (CMO) and 4 = chemical control – commercial herbicide Tordon, composed by Picloram (64 g.l-1) + 2,4-D (240 g.l-1), in the dosage of 5 l p.c.ha-1 (CQT)), associated to two systems of fertilization ( 1 = without fertilizer and 2 = with fertilizer). Two evaluation times (05/16/03 and 03/26/04) and two touch in pasture (1 = first touch and 2 = second touch) were considered on aspects related to the floristic survey and species frequency. The native leguminous plants generally appear in the lower stratus of the pasture (5.9 %), the undesirable ones appear in the upper stratus (5.0%). The chemical control promoted an increase in the grass frequency, as well as decreased the leguminous presence. The Paspalum notatum is the most frequent grass, and Desmodium incanum, mainly, decreased (among the legumes) in CQT. The fertilization favored the Trifolium polymorphum participation (2.0% vs 1.1% with and without fertilization, respectively). The mechanical control increased the frequency of Vernonia nudiflora in lower pasture stratus (5.7%) comparing to SC (3.6%). The autumn mechanical control with only one application during the experience time was more effi cient than the spring mechanical control

Exergoeconomic comparison of absorption refrigeration systems including a hibrid absorption-ejecto compression chiller

The study of absorption refrigeration systems has had increasing importance in recent years due to the fact that the primary energy that is used in an absorption system can be heat available from a residual source or even a renewable one. Therefore, these systems not only use energy that would be rejected by the environment, but also they avoid the consumption of expensive fossil or electrical energies. The production cost of the mechanical work necessary to obtain a kW of refrigeration for mechanical compression cycle is normally higher than the cost for recovering the needed heat to obtain the same kW in an absorption cycle. Also, the use of these systems reduces impact on the environment by decreasing the emission of CO2. We intend to show the performance of a hybrid absorption-ejecto compression chiller compared to conventional double- and single-effect water/lithium bromide systems, by means of an exergetic and exergoeconomic analysis of these configurations in order to calculate the exergy-based cost of a final product. The vapor compression refrigeration system is included in the results, as a comparisson to the performance of the absorption refrigeration systems analyzedEl estudio de los sistemas de refrigeración por absorción ha tomado una importancia creciente en los últimos años, ya que la energía primaria que es usada en un sistema de absorción puede ser calor disponible de una fuente residual o de una renovable. Por lo tanto, estos sistemas no sólo usan energía que sería rechazada al ambiente sino también, evitan el consumo de energías fósiles o eléctricas costosas. El costo de producción de trabajo mecánico necesario para obtener un kW de refrigeración para el ciclo de compresión mecánico es, normalmente, más alto que el costo para recuperar el calor necesario para obtener el mismo kW en un ciclo de absorción. También, el uso de estos sistemas reduce el impacto ambiental disminuyendo la emisión de CO2. Este artículo pretende mostrar el desempeño de un chiller híbrido de absorción-eyecto compresión comparado con sistemas de absorción convencionales de agua/bromuro de litio de simple y doble efecto, por medio de un análisis exergético y exergoeconómico de estas configuraciones a fin de calcular el costo con base exergética del producto final. Fue incluido un sistema de refrigeración por compresión de vapor en los resultados, como comparación del desempeño con los sistemas de refrigeración por absorción analizado

EXERGOECONOMIC COMPARISON OF ABSORPTION REFRIGERATION SYSTEMS INCLUDING A HIBRID ABSORPTION-EJECTO COMPRESSION CHILLER

The study of absorption refrigeration systems has had increasing importance in recent years due to the fact that the primary energy that is used in an absorption system can be heat available from a residual source or even a renewable one. Therefore, these systems not only use energy that would be rejected by the environment, but also they avoid the consumption of expensive fossil or electrical energies. The production cost of the mechanical work necessary to obtain a kW of refrigeration for mechanical compression cycle is normally higher than the cost for recovering the needed heat to obtain the same kW in an absorption cycle. Also, the use of these systems reduces impact on the environment by decreasing the emission of CO(2). We intend to show the performance of a hybrid absorption-ejecto compression chiller compared to conventional double- and single-effect water/lithium bromide systems, by means of an exergetic and exergoeconomic analysis of these configurations in order to calculate the exergy-based cost of a final product. The vapor compression refrigeration system is included in the results, as a comparisson to the performance of the absorption refrigeration systems analyzed

Diferentes métodos de controle de plantas indesejáveis em pastagem nativa

The study was conducted in a representative native pasture area in the transition between the Serra do Sudeste and Depressão Central of RS. The main undesirable species were represented by: carqueja (Baccharis trimera (Less.) DC.), caraguatá (Eryngium horridum (Spreng.) Less.) and alecrim (Vernonia nudiflora Less). It was evaluated the initial effect (until 60 days after application) of two methods of controlling undesirable plants on forage production, vegetation dynamics, and control efficiency: T1 - without control (control, SC), T2 - mechanical control (mechanic control, CM) and T3 - chemical control (commercial herbicide composed by Picloram (64 g/L) + 2.4-D (240 g/L), in the dosage of 5 L commercial product/ha, CQ). The treatments were organized in a complete block design, with four replications. There were no differences among treatments for the green dry matter of grasses and total DM. The forage legume biomass differed among treatments, with values of 587.9, 472.0 and 0 kg/ha of DM in the CM, CQ and SQ, respectively. The control efficiency of undesirable species in this study was 76.2% for CQ and 27.9% for CM when compared to SC. The species control efficiency, in terms of frequency of pasture components, showed that the CM treatment was not efficient at 60 days after treatment application in the control of Vernonia nudiflora (Alecrim) in the second touch (-27.7%) and Eryngium horridum (Caraguatá) in the first touch (-30.0%).O experimento foi desenvolvido em área de pastagem nativa representativa da transição entre a Serra do Sudeste e a Depressão Central do Rio Grande do Sul, onde as espécies indesejáveis foram representadas especialmente por carqueja (Baccharis trimera (Less.) DC.), caraguatá (Eryngium horridum (Spreng.) Less.) e alecrim (Vernonia nudiflora Less.). Foram avaliados os efeitos iniciais de dois métodos de controle de espécies indesejáveis (até 60 dias após aplicação) sobre a produção de forragem, a dinâmica da vegetação e a eficiência de controle: sem-controle; controle mecânico; e controle químico (herbicida comercial à base de Picloram [64 g/L] + 2,4-D [240 g/L], na dosagem de 5 L do produto comercial/ha). Os tratamentos foram arranjados em um delineamento em blocos ao acaso, com quatro repetições. A massa gramíneas verdes secas e a massa total de MS não diferiram entre os métodos de controle. Foram obtidos valores de 587,9; 472,0 e 0 kg de MS com o controle mecânico, o controle químico e sem-controle, respectivamente, o que comprova influência do método de controle sobre a massa de forragem de leguminosas. A eficiência de controle das espécies indesejáveis, em comparação à ausência de controle, foi de 76,2% para o controle químico e 27,9% para o controle mecânico. A eficiência de controle de espécies, sob aspectos de freqüência dos componentes da pastagem, evidenciou que o controle mecânico não foi eficiente aos 60 dias após aplicação no controle de plantas de alecrim no segundo toque (-27,7%) e plantas de caraguatá no primeiro toque (-30,0%)

Diferentes métodos de controle de plantas indesejáveis em pastagem nativa

The study was conducted in a representative native pasture area in the transition between the Serra do Sudeste and Depressão Central of RS. The main undesirable species were represented by: carqueja (Baccharis trimera (Less.) DC.), caraguatá (Eryngium horridum (Spreng.) Less.) and alecrim (Vernonia nudiflora Less). It was evaluated the initial effect (until 60 days after application) of two methods of controlling undesirable plants on forage production, vegetation dynamics, and control efficiency: T1 - without control (control, SC), T2 - mechanical control (mechanic control, CM) and T3 - chemical control (commercial herbicide composed by Picloram (64 g/L) + 2.4-D (240 g/L), in the dosage of 5 L commercial product/ha, CQ). The treatments were organized in a complete block design, with four replications. There were no differences among treatments for the green dry matter of grasses and total DM. The forage legume biomass differed among treatments, with values of 587.9, 472.0 and 0 kg/ha of DM in the CM, CQ and SQ, respectively. The control efficiency of undesirable species in this study was 76.2% for CQ and 27.9% for CM when compared to SC. The species control efficiency, in terms of frequency of pasture components, showed that the CM treatment was not efficient at 60 days after treatment application in the control of Vernonia nudiflora (Alecrim) in the second touch (-27.7%) and Eryngium horridum (Caraguatá) in the first touch (-30.0%).O experimento foi desenvolvido em área de pastagem nativa representativa da transição entre a Serra do Sudeste e a Depressão Central do Rio Grande do Sul, onde as espécies indesejáveis foram representadas especialmente por carqueja (Baccharis trimera (Less.) DC.), caraguatá (Eryngium horridum (Spreng.) Less.) e alecrim (Vernonia nudiflora Less.). Foram avaliados os efeitos iniciais de dois métodos de controle de espécies indesejáveis (até 60 dias após aplicação) sobre a produção de forragem, a dinâmica da vegetação e a eficiência de controle: sem-controle; controle mecânico; e controle químico (herbicida comercial à base de Picloram [64 g/L] + 2,4-D [240 g/L], na dosagem de 5 L do produto comercial/ha). Os tratamentos foram arranjados em um delineamento em blocos ao acaso, com quatro repetições. A massa gramíneas verdes secas e a massa total de MS não diferiram entre os métodos de controle. Foram obtidos valores de 587,9; 472,0 e 0 kg de MS com o controle mecânico, o controle químico e sem-controle, respectivamente, o que comprova influência do método de controle sobre a massa de forragem de leguminosas. A eficiência de controle das espécies indesejáveis, em comparação à ausência de controle, foi de 76,2% para o controle químico e 27,9% para o controle mecânico. A eficiência de controle de espécies, sob aspectos de freqüência dos componentes da pastagem, evidenciou que o controle mecânico não foi eficiente aos 60 dias após aplicação no controle de plantas de alecrim no segundo toque (-27,7%) e plantas de caraguatá no primeiro toque (-30,0%)