Organic farm conventionalisation and farmer practices in China, Brazil and Egypt.

Certified organic agriculture stipulates a range of principles and standards, which govern farmer practices. The recent global expansion of organic agriculture has raised new challenges for organic agriculture, particularly whether management practices in organic farms are subject to the forces of conventionalisation. We studied changes in agroecological practices in certified organic farms in China, Brazil and Egypt. The study takes departure in the conventionalisation hypothesis and the analysis is framed using organic and agroecological principles. The study focuses on agroecological design principles, inherent to organic agriculture, of diversity in crop production, pest, disease and weed management, and soil fertility management. The research design was as a multiple case study of five cases in China, Brazil and Egypt. We show that the adoption of organic agriculture has induced fundamental changes in organic farmer management practices, although agroecological practices of organic farmers do not fulfil organic principles. The forces of conventionalisation exert a strong influence on changes in organic farmer practices. Organic ‘niche’ market crops with a high-value influence organic farmers’ management decisions, particularly regarding the prioritisation of diversity in the cropping systems for agroecological purposes. The farming systems have therefore not undergone major changes of their cropping patterns. Furthermore, there was a general heavy reliance upon input substitution for pest and soil fertility management. This study thus presents new data and a novel analysis of the implications at the farm scale of the global expansion of organic agriculture, and the influence of conventionalisation on farmers practices

Right-handed Neutrinos in Low-Energy Neutrino-Electron Scattering

In this paper a scenario admitting the participation of the exotic scalar coupling of the right-handed neutrinos in addition to the standard vector and axial couplings of the left-handed neutrinos in the weak interactions is considered. The research is based on the low-energy $(\nu_{\mu} e^{-})$ and $(\nu_{e} e^{-})$ scattering processes. The main goal is to show how the presence of the right-handed neutrinos in the above processes changes the laboratory differential cross section in relation to the Standard Model prediction. Both processes are studied at the level of the four-fermion point interaction. Neutrinos are assumed to be polarized Dirac fermions and to be massive. In the laboratory differential cross section, the new interference term between the standard vector coupling of the left-handed neutrinos and exotic scalar coupling of the right-handed neutrinos appears which does not vanish in the limit of massless neutrino. This additional contribution, including information about the transverse components of neutrino polarization, generates the azimuthal asymmetry in the angular distribution of the recoil electrons. This regularity would be a signature of the participation of the right-handed neutrinos in the neutrino-electron scattering. The future low-energy high-precision neutrino-electron scattering experiments using the strong and polarized artificial neutrino source would allow to search for the exotic effects coming from the R-handed neutrinos.Comment: REVTeX, 9 pages, 5 eps figures; published in Phys. Lett. B 555, 215-226 (2003

The B -> D* l nu Form Factor at Zero Recoil

We describe a model independent lattice QCD method for determining the deviation from unity for h_{A1}(1), the B -> D* l nu form factor at zero recoil. We extend the double ratio method previously used to determine the B -> D l nu form factor. The bulk of statistical and systematic errors cancel in the double ratios we consider, yielding form factors which promise to reduce present theoretical uncertainties in the determination of V_{cb}. We present results from a prototype calculation at a single lattice spacing corresponding to beta=5.7.Comment: Lattice99(heavyquarks); 3 pgs, LaTe

Reaction of passion fruit genotypes to root knot nematodes (Meloidogyne incognita e Meloidogyne javanica)

O nematóide das galhas é apontado como uma das causas da baixa produtividade de inúmeras lavouras de maracujá-azedo. O presente trabalho teve como objetivo avaliar a reação de genótipos de maracujazeiro-azedo aos nematóides das galhas, formado pela mistura de Meloidogyne incognita e Meloidogyne javanica. O ensaio foi conduzido em casa-de-vegetação utilizando o delineamento de blocos casualizados, com quatro repetições e 6 plantas úteis por unidade experimental, em esquema de parcela subdividida com quatro níveis de inóculo: 0; 25; 50 e 75 ovos/ml de substrato, correspondendo as populações iniciais de 0; 3.000; 6.000 e 9.000 ovos por muda, respectivamente, distribuídos nas parcelas e quatro genótipos: Redondão, Yelow Máster FB-100, F1 (Marília x Roxo Australiano) e MAR 20#41, nas subparcelas, totalizando 16 tratamentos. Mudas produzidas em bandejas de poliestireno, contendo substrato artificial à base de vermiculita mais casca de Pinus spp. foram inoculadas aos 40 dias após a semeadura. Avaliações no crescimento vegetativo das plantas e número de galhas foram realizadas noventa dias após a inoculação. Não foram observadas diferenças significativas no crescimento das plantas em função do nível de inóculo. O uso de 3.000 e 6.000 ovos do nematóide por planta resultou em diferença significativa no número de galhas. O genótipo Redondão foi superior às demais cultivares quanto às variáveis relacionadas ao crescimento vegetativo, exceto quanto à massa da matéria fresca de raiz. O genótipo Redondão apresentou moderada resistência quando inoculado com 3.000 ovos por planta do nematóide e moderada suscetibilidade com 6.000 e 9.000 ovos por planta, enquanto o híbrido F1 (Marília x Roxo Australiano) mostrou moderada suscetibilidade com 3.000 ovos por planta e suscetibilidade com 6.000 e 9.000 ovos por planta. Os demais genótipos mostraram moderada suscetibilidade nas três diferentes concentrações de inóculo de Meloidogyne spp (Meloidogyne incognita e Meloidogyne javanica). _____________________________________________________________________________________ ABSTRACTThe root knot nematode has been the main reasons for low productivity of several passionfruit plantations in Brazil. The aim of this study was to evaluate the reaction of passionfruit genotypes to knot root nematode Meloidogyne incognita e Meloidogyne javanica. The experiment was carried out in greenhouse with four randomized blocks and six plants per experimental unit, with a split plot design and four levels of inoculum (0; 25; 50 e 75 eggs/ml of substrate, corresponding to initial population of 0; 3.000; 6.000 e 9.000 eggs per seedling, respectively), as the main plot four genotypes (Redondão, Yelow Máster FB-100, F1 (Marília x Roxo Australiano) and MAR 20#41), were the sub plots, with a total of sixteen treatments. Seedlings were grown in polystyrene trays, with an artificial substrate of vermiculite plus Pinus spp bark inculated 40 days after planting. Evaluations of plant growth and number of root knot were carried out ninety days after inoculation. There were no significant differences on plant growth in relation to level of inoculum. The use of 3.000 and 6.000 eggs of nematodes/plant led to a significant difference in number of root knot. The genotype Redondão was superior for all parameters related to vegetative growth, with exception of root fresh weight. The genotype Redondão showed moderated resistance, when inoculated with 3000 eggs of nematode per plant, while the hybrid F1 (Marília x Roxo Australiano) showed moderated susceptibility with 3.000 eggs per plant and susceptibility with 6.000 and 9.000 eggs per plant. The other genotypes showed moderated susceptibility at all different inoculum concentration of Meloidogyne spp (Meloidogyne incognita and Meloidogyne javanica)

Classic and spatial shift-share analysis of state-level employment change in Brazil

This paper combines classic and spatial shift-share decompositions of 1981 to 2006 employment change across the 27 states of Brazil. The classic shift-share method shows higher employment growth rates for underdeveloped regions that are due to an advantageous industry-mix and also due to additional job creation, commonly referred to as the competitive effect. Alternative decompositions proposed in the literature do not change this broad conclusion. Further examination employing exploratory spatial data analysis (ESDA) shows spatial correlation of both the industry-mix and the competitive effects. Considering that until the 1960s economic activities were more concentrated in southern regions of Brazil than they are nowadays, these results support beta convergence theories but also find evidence of agglomeration effects. Additionally, a very simple spatial decomposition is proposed that accounts for the spatially-weighted growth of surrounding states. Favourable growth in northern and centre-western states is basically associated with those states’ strengths in potential spatial spillover effect and in spatial competitive effect

Reaction of ten passionfruit genotypes (Passiflora edulis Sims f. flavicarpa Deneger) and Passiflora alata dryand to the race 1 of Meloidogyne incognita

O nematóide das galhas causa perdas econômicas para a cultura do maracujazeiro. Esse experimento apresenta a reação de dez progênies de maracujazeiro azedo (Havaiano, Marília Seleção Cerrado, Redondão, Roxo Fiji x Marília, MAR 20#19, MAR 20#32, MAR 20#42, MAR 20#43, MAR 20#45, MAR 20#58) e do maracujazeiro doce, à raça 1 de Meloidogyne incognita. O experimento foi conduzido sob condição de casa de vegetação. Mudas de 30 dias foram inoculadas com 1.200 ovos/planta de M. incognita (raça 1). Noventa dias após a inoculação, foram avaliados o crescimento vegetativo e o número de galhas por planta. As progênies MAR 20#19, MAR 20#32, MAR 20#42, MAR 20#43, MAR 20#45, Marília Seleção Cerrado (MSC), Redondão e híbrido F1 (Roxo Fiji x Marília) foram moderadamente resistentes à raça 1 de M. incognita. Por outro lado, as progênies Havaiano e MAR 20#58 foram moderadamente susceptíveis, apresentando 65,48% e 43,83% de galhas/planta, respectivamente, em relação à testemunha. Aparentemente, as progênies mais vigorosas mostraram-se mais resistentes, enquanto as progênies menos vigorosas mostraram-se mais susceptíveis ao nematóide. ____________________________________________________________________________________ ABSTRACTThe knot root nematode causes economic losses to passionfruit. The objective of this work wat to study the reaction of ten progenies of yellow passionfruit (Havaiano, Marília Seleção Cerrado, Redondão, F1 (Roxo Fiji x Marília), MAR 20#19, MAR 20#32, MAR 20#42, MAR 20#43, MAR 20#45, MAR 20#58) and the sweet passionfruit to race 1 of Meloidogyne incognita. The experiment was carried out under greenhouse conditions. Thirty-day-old seedlings were inoculated with the M. incognita (1.200 eggs/plant). Ninety days after inoculation, plant growth parameters and number of galls were observed. The progenies MAR 20#19, MAR 20#32, MAR 20#42, MAR 20#43, MAR 20#45, Marília Seleção Cerrado (MSC), Redondão and hybrid F1 (Roxo Fiji x Marília) were moderately resistant to race 1 of M. incognita. On the other hand, the progenies Havaiano and MAR20#58 were moderately susceptible, showing 65,48% and 43,83% of galls/plant, respectively, in relation to control. Aparently, the progenies more vigorous were more resistant, while the progenies less vigorously were more susceptibles to nematodes

Constraints From Gauge Coupling Unification On The Scale Of Supersymmetry Breaking

We reanalyze precision LEP data and coupling constant unification in the minimal supersymmetric $SU(5)$ model including the evolution of the gaugino masses. We derive general bounds on the primordial gaugino supersymmetry-breaking mass-scale $m_{1/2}$ in terms of the various input parameters. The model cannot accommodate m_{1/2}<1\TeV for values of \as < 0.115, even for extreme $1-\sigma$ values of the other inputs. We emphasize the sensitivity of this type of calculations to the various input parameters.Comment: 9 pages, 1 figure not included, ACT-10/9

The Interplay between Colon Cancer Cells and Tumour-Associated Stromal Cells Impacts the Biological Clock and Enhances Malignant Phenotypes

Cancer cells interrelate with the bordering host microenvironment that encompasses the extracellular matrix and a nontumour cellular component comprising fibroblasts and immune-competent cells. The tumour microenvironment modulates cancer onset and progression, but the molecular factors managing this interaction are not fully understood. Malignant transformation of a benign tumour is among the first crucial events in colorectal carcinogenesis. The role of tumour stroma fibroblasts is well-described in cancer, but less well-characterized in benign tumours. In the current work we utilized fibroblasts isolated from tubulovillous adenoma, which has high risk for malignant transformation, to study the interaction between benign tumour stroma and the circadian clock machinery. We explored the role of the biological clock in this interplay taking advantage of an experimental model, represented by the co-culture of colon cancer cells with normal fibroblasts or tumour-associated fibroblasts, isolated from human colorectal tumour specimens. When co-cultured with tumour-associated fibroblasts, colon cancer cells showed alterations in their circadian and metabolic parameters, with decreased apoptosis, increased colon cancer cell viability, and increased resistance to chemotherapeutic agents. In conclusion, the interactions among colon cancer cells and tumour-associated fibroblasts affect the molecular clockwork and seem to aggravate malignant cell phenotypes, suggesting a detrimental effect of this interplay on cancer dynamics

Direct Extraction of QCD Lambda MS-bar from e+e- Jet Observables

We directly fit the QCD dimensional transmutation parameter, Lambda MS-bar, to experimental data on e+e- jet observables, making use of next-to-leading order (NLO) perturbative calculations. In this procedure there is no need to mention, let alone to arbitrarily vary, the unphysical renormalisation scale mu, and one avoids the spurious and meaningless ``theoretical error'' associated with standard alpha_s determinations. PETRA, SLD, and LEP data are considered in the analysis. An attempt is made to estimate the importance of uncalculated next-NLO and higher order perturbative corrections, and power corrections, by studying the scatter in the values of Lambda MS-bar obtained for different observables.Comment: 46 pages, 22 figure