Establishment of new crops for the production of natural rubber.

Natural rubber is a unique biopolymer of strategic importance that, in many of its most significant applications, cannot be replaced by synthetic alternatives. The rubber tree Hevea brasiliensis is the almost exclusive commercial source of natural rubber currently and alternative crops should be developed for several reasons, including: a disease risk to the rubber tree that could potentially decimate current production, a predicted shortage of natural rubber supply, increasing allergic reactions to rubber obtained from the Brazilian rubber tree and a general shift towards renewables. This review summarizes our knowledge of plants that can serve as alternative sources of natural rubber, of rubber biosynthesis and the scientific gaps that must be filled to bring the alternative crops into production.

Botrychium matricariifolium A. Br. ex Koch, una nova esp��cie per a la flora del mass��s del Montseny = Botrychium matricariifolium A. Br. ex Koch, a new species for the flora of the Montseny massif (NE Iberian Peninsula)

Nota breu sobre la descripci�� de Botrychium matricariifolium A. Br. ex Koch al mass��s del Montseny

Improvement of a testing apparatus for dynamometry: procedures for penetrometry and influence of strain rate to quantify the tensile strength of soil aggregates

Soil penetration resistance (PR) and the tensile strength of aggregates (TS) are commonly used to characterize the physical and structural conditions of agricultural soils. This study aimed to assess the functionality of a dynamometry apparatus by linear speed and position control automation of its mobile base to measure PR and TS. The proposed equipment was used for PR measurement in undisturbed samples of a clayey "Nitossolo Vermelho eutrof��rrico" (Kandiudalfic Eutrudox) under rubber trees sampled in two positions (within and between rows). These samples were also used to measure the volumetric soil water content and bulk density, and determine the soil resistance to penetration curve (SRPC). The TS was measured in a sandy loam "Latossolo Vermelho distr��fico" (LVd) - Typic Haplustox - and in a very clayey "Nitossolo Vermelho distrof��rrico" (NVdf) - Typic Paleudalf - under different uses: LVd under "annual crops" and "native forest", NVdf under "annual crops" and "eucalyptus plantation" (> 30 years old). To measure TS, different strain rates were applied using two dynamometry testing devices: a reference machine (0.03 mm s-1), which has been widely used in other studies, and the proposed equipment (1.55 mm s-1). The determination coefficient values of the SRPC were high (R�� > 0.9), regardless of the sampling position. Mean TS values in LVd and NVdf obtained with the proposed equipment did not differ (p > 0.05) from those of the reference testing apparatus, regardless of land use and soil type. Results indicate that PR and TS can be measured faster and accurately by the proposed procedure.

La mortalit�� par tumeur maligne chez les ouvriers d'une fabrique de caoutchouc en Suisse: ��tude ��pid��miologique, 1955-1975. [Cancer mortality among the workers of a Swiss rubber goods factory. Epidemiological study, 1955-75].

In an epidemiologic investigation of mortality among workers in a Swiss rubber-goods factory the cancer mortality in the period 1955-1975 has been studied in all male workers active on 1 January 1955 in (a) a rubber-goods factory and (b) a munitions factory, the latter as reference population. The two groups numbered some 1000 each. Both factories were located in the same Central Swiss village where no other industry was present. Mortality in each industry is compared with that in the Swiss population in general (SMR) and the mortalities of the two industries are compared with each other. The results tend to confirm that rubber workers are exposed to a higher risk of cancer mortality. Three particular types of cancer are briefly discussed: cancer of the stomach, of the lower urinary tract, and glioblastoma.

L'alian��a Polygonion avicularis Br.-Bl. ex Dich. 1933 als Pirineus Catalans

L'an��lisi de nombrosos inventaris procedents dels Pirineus centrals i orientals ens ha dut a realitzar una revisi�� de I'alian��a Polygonion avicularis Br.-Bl. ex Dich 1933 en aquesta ��rea. Reconeixem fins al moment sis associacions per a les quals donem la seva caracteritzaci�� flor��stica i ecologica, aix�� com la seva distribuci�� als Pirineus catalans. Descrivim, a m��s, una subass. scleranthetosum uncinatae del Rumici-Spergularietum rubrae, comunitat altimontana i subalpina pr��pia dels s��ls calcigats.

Rubber Buffings for Bridge Approach Expansion Joints, MLR-01-01, 2001

Many of the bridges in the state of Iowa have type ���CF���, ���EE���, or ���EF��� expansion joints installed in the bridge approach slabs. These joints, which are typically 4��� wide, are currently filled with a foam expansion joint material that is covered with a sealant. Over time the sealant begins to pull off of the walls of the joint and it ultimately fails. The joint, which is now exposed to the weather, is then filled with water and solids. The foam joint material, which is lighter than water, floats out of the joint onto the highway. This foam resembles a large 4��� X 6��� plank and poses a threat to motorists. A possible solution to this problem would be to replace the foam material with rubber buffings. Rubber buffings are a by-product of the tire retread industry.

Efeito da germina����o de soja CV. BR-13 e Paran�� sobre ��cido f��tico, f��sforo total e inibidores de tripsina

Este trabalho foi conduzido para avaliar o efeito da germina����o sobre os constituintes antinutricionais da soja, ��cido f��tico, P total e inibidores de tripsina, que interferem na utiliza����o de prote��nas e outras subst��ncias. A diminui����o no aproveitamento de nutrientes resulta em inibi����o de crescimento, hipoglicemia ou danos a tecidos animais. Para os ensaios foram utilizadas as cultivares de soja (Glycine max (L.) Merrill ) BR-13 e Paran��. As sementes foram incubadas em c��mara de germina����o a 25��C e 100% de umidade, de 0 a 72 horas, com coleta de amostras em intervalos eq��idistantes de seis horas. A cultivar Paran�� apresentou teores superiores de ��cido f��tico, P total e inibidores de tripsina, em rela����o �� cultivar BR-13. As an��lises de vari��ncia e compara����es entre m��dias indicaram que houve aumentos significativos (p < 0,05) nos teores de P total (8,5% e 3,6% nas cultivares BR-13 e Paran��, respectivamente) e nos n��veis de inibidores de tripsina (22,05% e 17,10% nas cultivares BR-13 e Paran��, respectivamente), e redu����es nos teores de ��cido f��tico (15,96% e 9,46% nas cultivares BR-13 e Paran��, respectivamente), em 72 horas de germina����o.

Laboratory Evaluation of Asphalt-Rubber in Asphalt Paving Mixture, MLR-89-15, 1990

Interest in the use of ground rubber from used tires as a hot asphalt mix binder has been increasing due to the magnitude of the disposal problem posed by the annual addition of millions of waste tires to the refuse stream. This study evaluates, through laboratory means, the performance of asphalt-rubber as a hot mix binder as compared to conventional asphalt. The results indicate that asphalt-rubber outperforms its base asphalt in mixes of identical gradation and comparable void content on tests that are heavily dependent on binder characteristics (resilient modulus and indirect tension). An appreciable increase in rut resistance due to the use of asphalt-rubber is not indicated.

Controle qu��mico da ferrugem (Hemileia vastatrix Berk &amp; Br.) do cafeeiro atrav��s de diferentes esquemas de aplica����o

O presente trabalho foi desenvolvido com o objetivo de testar os diferentes esquemas de controle qu��mico da ferrugem do cafeeiro dispon��veis, durante o per��odo de 1994 a 1996 em S��o Sebasti��o do Para��so, MG. Os tratamentos foram constitu��dos por esquemas preventivos, baseados em fungicidas c��pricos (oxicloreto de cobre e ��xido cuproso), curativos, baseados em fungicidas sist��micos (grupo dos triazois) e mistos (associa����o de esquemas curativos e preventivos). As datas de aplica����o foram previamente fixadas. Os resultados obtidos demonstraram que: a) a aplica����o de esquemas de controle por meio de datas pr��-fixadas tem permitido a eleva����o da ferrugem ao final do seu ciclo; b) o fungicida triadimenol 1,5%, associado ao inseticida dissulfoton 7,5%, granulado, aplicado ao solo no m��s de dezembro, na dosagem de 40 kg/ha do produto comercial, foi o ��nico tratamento que manteve baixos ��ndices de ferrugem durante o ciclo da doen��a; c) os tratamentos aplicados por meio do sistema radicular, triadimenol e cyproconazole, foram beneficiados pela associa����o com o inseticida dissulfoton.

Phenotypic stability and genetic gains in six-year girth growth of Hevea clones

Rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) M��ell. Arg.] budgrafts of seven clones were evaluated on five contrasting sites in the plateau region of the S��o Paulo State, Brazil. The objective of this work was to study the phenotypic stability for girth growth. The experimental design was a randomized block design with three replications and seven treatments. Analysis of variance of girth at six-year plant growth indicated a highly significant clone x site interaction. Only linear sites and clone x site components of clone x year interaction were significant, indicating that the performance of clones over sites for this trait could be predicted. The clones GT 1 and PB 235 showed the greatest stability in relation to girth growth, with foreseen responses to change, introduced in the sites. The clones PB 235 and IAN 873 showed significative difference in relation to regression coefficient, representing clones with specific adaptability on favorable and unfavorable sites respectively. The clone GT 1 became the most promissory one in the study of stability and adaptability even showing low girth growth. Expected genetic gains from planting sites, along with estimates of clonal variance and repeatability of clonal means are generally greatest or close to the greatest when selection is done at the same site.

CEVADA BR 2: CULTIVAR DE CEVADA CERVEJEIRA RESISTENTE �� MANCHA-RETICULAR CAUSADA POR PYRENOPHORA TERES

A Cevada BR 2, criada pela Embrapa-Centro Nacional de Pesquisa de Trigo (CNPT), foi lan��ada para cultivo em 1989. Originou-se de sete plantas selecionadas em F3 do cruzamento FM 424/TR 206, realizado em 1979, em Passo Fundo, RS. A BR 2 �� uma cevada de primavera, do tipo de duas fileiras de gr��os, com ciclo precoce, ampla adapta����o e porte baixo. �� a primeira cultivar brasileira resistente a Pyrenophora teres, agente causal da mancha-reticular, principal mol��stia da cevada no Brasil. Em oito anos de avalia����o no Ensaio Nacional de Cevada, conduzido em 12 locais da Regi��o Sul, a BR 2 rendeu entre 1.621 e 4.014 kg/ha de gr��os de primeira qualidade, superando a cultivar Antarctica 05 em 3% no RS e SC, em 13% no PR, e em 6% na m��dia dos 96 experimentos (12 locais x 8 anos). Na lavoura, a BR 2 tem produzido rendimentos acima de 5.000 kg/ha. Aprovada como cervejeira em 1992, ocupou 30% da ��rea semeada em 1993 e 90% em 1997. A BR 2 representa um marco no progresso do melhoramento gen��tico da cevada no pa��s, contribuindo decisivamente para o aumento da competitividade da produ����o dom��stica.