Agregação de Latossolo vermelho distrófico típico relacionada com o manejo na região dos cerrados no Estado de Minas Gerais.

As consequencias diretas do manejo inadequado do solo sao a erosao, a reducao da produtividade e a perda de sua sustentabilidade. Os indicadores da qualidade da estrutura do solo sao importantes ferramentas para avaliar a sustentabilidade dos sistemas de manejo. Este estudo objetivou avaliar a agregacao de um Latossolo Vermelho distrofico tipico sob diferentes sistemas de manejo na regiao dos cerrados em Sete Lagoas (MG). Dentre os sistemas de manejo estudados, a semeadura direta foi o que apresentou a maior percentagem de agregados nas classe > 2mm, menores nas classes 2mm (r = 0,92) e correlacao negativa com classes de agregados < 2 (r = .0,92) e < 1 mm (r = .0,93). Esses aspectos ressaltam o efeito benefico da semeadura direta, contribuindo para o manejo sustentado do solo

Resistência a penetração e permeabilidade de Latossolo Vermelho distrófico típico sob sistemas de manejo na região dos cerrados.

As consequencias diretas do manejo inadequado do solo sao a erosao, a reducao da produtividade e a perda da sustentabilidade. Objetivou-se com este estudo avaliar a resistencia a penetracao (RP) e a permeabilidade do solo a agua (PER) sob sistemas de manejo em uso na regiao de cerrados. O estudo foi realizado na Embrapa Milho e Sorgo, em Sete Lagoas (MG), em Latossolo Vermelho distrofico tipico textura muito argilosa fase cerrado. O cerrado nativo propiciou menor densidade do solo, maior macroporosidade, maior volume total de poros, consequentemente, menor resistencia a penetracao (0,84 a 2,09 MPa) e maior permeabilidade (95 mmh-1). Foram verificados maiores valores de resistencia a penetracao vertical para o sistema com preparo convencional com arado de discos e cultivo em rotacao com milho e feijao, na profundidade de 15-30 cm no solo, sendo o valor 3,04 MPa classificado como alto, podendo ser um indicativo de restricao ao desenvolvimento radicular e compactacao do solo. De modo geral, ao longo do perfil do solo, os maiores valores de RP foram observados para o plantio direto. Nao houve diferencas significativas na PER entre os sistemas de manejo, estando os valores na faixa de 6 a 14 mmh-1, sendo a mesma classificada como lenta; estes valores foram bem inferiores aos do sistema em equilibrio. Os atributos fisicos utilizados neste estudo, como indicadores da qualidade do solo, apresentaram boa performance na distincao dos efeitos proporcionados pelos sistemas de manejo em relacao ao sistema em equilibrio, contribuindo para o monitoramento do manejo sustentavel de solos da regiao dos cerrados

Public Price Reporting, Marketing Channel Selection, and Price Discovery: The Perspective of Cow/Calf Producers in the Dakotas

Cow/calf producers operating in the Dakotas were surveyed on their price discovery strategies, marketing channel preferences, and their perceptions of how regime change in the public price reporting system for fed cattle affected the beef industry in general and the cow/calf industry in particular. Survey results indicate cow/calf producers consider local institutions (auction barns, etc.) to be more reliable for price discovery than regional or national institutions (futures market, USDA public price reports, satellite auctions, etc.). The auction barn marketing channel is the preferred channel for marketing cattle and is considered the most reliable source of market information by producers. Dakota cow/calf producers perceive livestock mandatory price reporting as benefiting the beef industry in general, but consider public price reports to be less reliable than local sources of market information.beef supply chain, cow-calf marketing, marketing channel, price discovery, public price reporting, Livestock Production/Industries,

Secondary metabolites of Phlomis viscosa and their biological activities

Further phytochemical studies on the aerial parts of Phlomis viscosa (Lamiaceae) led to the isolation of 24 compounds: 3 iridoid glycosides, 10 phenylethanoid glycosides, a megastigmane glycoside and a hydroquinone glycoside, as well as 2 lignan glucosides and 7 neolignan glucosides, 1 of which is new (17b). Compound 17b was obtained as a minor component of an inseparable mixture (2:1) of 2 neolignan glucosides (17a/b), and characterized as 3',4-O-dimethylcedrusin 9-O-b -glucopyranoside. Full NMR data of the known 8-O-4' neolignan glucoside, erythro-1-(4-O-b-glucopyranosyl-3-methoxyphenyl)- 2-{2-methoxyl-4-[1-(E)-propene-3-ol]-phenoxyl}-propane-1,3-diol (18) are also reported. All isolated compounds were screened for cell growth inhibition versus 3 tumor cell lines (MCF7, NCI-H460, and SF-268) and several phenylethanoid glycosides were found to possess weak antitumoral activity. The phenylethanoid glycosides were also evaluated for their free radical (DPPH) scavenging, antibacterial and antifungal activities. The free radical (DPPH) scavenging activities of verbascoside (4), isoacteoside (5), forsythoside B (10), myricoside (13) and samioside (14) were found to be comparable to that of dl-a -tocopherol. Compounds 4, 5, 10 and 14 (MIC: 500 m g/mL) as well as Leucosceptoside A (8) and 13 (MIC:1000 m g/mL) showed very weak activity against Gram (+) bacteria

A New Combined European Permanent Network Station Coordinates Solution

The EUREF (International Association of Geodesy (IAG) Reference Frame Sub-Commission for Europe) network of continuously operating GPS stations (EPN) was primarily established for reference frame maintenance, and also plays an important role for geodynamical research in Europe. The main goal of this paper is to obtain an independent homogeneous time-series of the EPN station coordinates, which is also available in SINEX format. A new combined solution of the EPN station coordinates was computed. The combination was performed independently for every week, in three steps: 1. the stated constraints on the coordinates were removed from the individual solutions of the Analysis Centers; 2. the de-constrained solutions were aligned to ITRF2000; 3. the resulting solutions were combined using the Helmert block-ing technique. All the data from GPS week 900 to week 1302 (April 1997 - December 2004) were used. We investigated in detail the behavior of the transformation parameters aligning the new combined solution to ITRF2000. In general, the time-series of the transformation parameters show a good stability in time although small systematic effects can be seen, most likely caused by station instabilities. A comparison of the new combined solution to the official EUREF weekly combined solution is also presented

A rapid electrophoretic technique for human and Chinese hamster galactokinase

In this paper a simple direct staining method is described for the detection of the human and Chinese hamster forms of galactokinase as separated by electrophoresis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47602/1/439_2004_Article_BF00394199.pd