EFICIÊNCIA ECONÔMICA DA CAFEICULTURA NO SUL DE MINAS GERAIS: UMA APLICAÇÃO DA FRONTEIRA DE PRODUÇÃO

Through this study, we sought to evaluate the economic efficiency of the allocation of productive resources of coffee inthe south of Minas Gerais. The cities surveyed are among the largest producers in the south of this state: Alfenas, Guaxupé, SãoSebastião do Paraíso, Varginha and Tres Pontas, totaling 46 coffee plantations. This study is based on the principles of the theory ofproduction and cost, using the stochastic production frontier model to measure and estimate the production function. The technicalcoefficients refer to the agricultural years 2006/2007, 2007/2008 and 2008/2009, which were adjusted for the 2008/2009 harvest. Onaverage, farmers have an economic efficiency of 70.3%. Coffee producers were considered cost efficient when the measure ofeconomic efficiency (EE) was equal to or greater than 90.0%. The percentage of farmers who have achieved this minimum score ofefficiency stands at 28.2%. The results indicate inefficient use of productive resources in most cases, both technically and economicallyPor meio deste estudo, buscou-se avaliar a eficiência econômica da alocação dos recursos produtivos da cafeicultura no sulde Minas Gerais. Os municípios pesquisados estão entre os maiores produtores do sul do estado: Alfenas, Guaxupé, São Sebastiãodo Paraíso, Varginha e Três Pontas, totalizando 46 propriedades de café. Este estudo baseia-se nos princípios da teoria da produçãoe do custo e utiliza o modelo de fronteira estocástica para a mensuração e a estimativa da função de produção. Os coeficientes técnicosreferem-se aos anos agrícolas 2006/2007, 2007/2008 e 2008/2009, que foram ajustados para a safra 2008/2009. Em média, oscafeicultores apresentam eficiência econômica de 70,3%. Considerou-se o produtor de café economicamente eficiente aquele em quea medida de eficiência econômica (EE) fosse igual ou maior que 90,0%, sendo o percentual de cafeicultores que atingiram esse escoremínimo de eficiência de 28,2%. Os resultados indicaram uso ineficiente dos recursos produtivos na maioria dos casos, tanto técnicaquanto economicamente

EFICIÊNCIA ECONÔMICA DA CAFEICULTURA NO SUL DE MINAS GERAIS: UMA ABORDAGEM PELA ANÁLISE ENVOLTÓRIA DE DADOS

Por meio deste estudo, buscou-se avaliar a eficiência econômica da alocação dos recursos produtivos da cafeicultura no Sul de Minas Gerais. Os municípios pesquisados estão entre os maiores produtores do sul do Estado, a exemplo de Alfenas, Guaxupé, São Sebastião do Paraíso, Varginha e Três Pontas, totalizando 46 propriedades de café. Este estudo baseia-se nos princípios da teoria da produção e do custo e utiliza o modelo de Análise Envoltória de Dados para avaliar a eficiência econômica dos cafeicultores pesquisados. Os coeficientes técnicos referem-se aos anos agrícolas 2006/2007, 2007/2008 e 2008/2009, que foram ajustados para a safra 2008/2009. Em média, os cafeicultores apresentam eficiência econômica de 64,08%. Considerou-se o produtor de café economicamente eficiente aquele em que a medida de eficiência econômica (EE) fosse igual ou maior 90,0%, e o percentual de cafeicultores que atingiram esse escore mínimo de eficiência foi de 13,4%. Os resultados indicaram uso ineficiente dos recursos produtivos na maioria dos casos, tanto técnica quanto economicamente

CUSTOS DE PRODUÇÃO DA CAFEICULTURA NO SUL DE MINAS GERAIS

A spreadsheet featuring production costs for coffee in different productivity ranges is presented in this study. The survey is based on the theory of costs and the study location was the southern region of the state of Minas Gerais, where data on 48 coffee production units were gathered during the 1998/99 harvest. Taking the economical indexes resulting from research into consideration, one may infer that expenses on variable resources represent the greater portion of the final cost of coffee. The items which affected production costs the most were crop formation, in the case of unvariable costs, and the expenses on labor, especially the seasonal kind. It was also concluded that coffee culture belongs to the scale-economy kind and , as a whole, the 1998/99 coffee harvest ended up economically profittable

Replication Protein A presents canonical functions and is also involved in the differentiation capacity of Trypanosoma cruzi

Submitted by Luciane Willcox ([email protected]) on 2017-04-19T13:31:24Z No. of bitstreams: 1 Replication Protein A Presents Canonical Functions and Is Also Involved in the Differentiation Capacity of Trypanosoma cruzi.pdf: 2837768 bytes, checksum: 4bd66cfcd5f9128f11a7dd42e4e9ed77 (MD5)Approved for entry into archive by Manoel Barata ([email protected]) on 2017-07-26T11:56:07Z (GMT) No. of bitstreams: 1 Replication Protein A Presents Canonical Functions and Is Also Involved in the Differentiation Capacity of Trypanosoma cruzi.pdf: 2837768 bytes, checksum: 4bd66cfcd5f9128f11a7dd42e4e9ed77 (MD5)Made available in DSpace on 2017-07-26T11:56:07Z (GMT). No. of bitstreams: 1 Replication Protein A Presents Canonical Functions and Is Also Involved in the Differentiation Capacity of Trypanosoma cruzi.pdf: 2837768 bytes, checksum: 4bd66cfcd5f9128f11a7dd42e4e9ed77 (MD5) Previous issue date: 2016Instituto Butantan. Laboratório Especial de Ciclo Celular. São Paulo, SP, Brasil. / Instituto Butantan. Center of Toxins. Immune Response and Cell Signaling—CeTICS. São Paulo, SP, Brazil.Instituto Butantan. Laboratório Especial de Ciclo Celular. São Paulo, SP, Brasil. / Instituto Butantan. Center of Toxins. Immune Response and Cell Signaling—CeTICS. São Paulo, SP, Brazil.Universidade Estadual Paulista Júlio de Mesquita Filho. Instituto de Biociências. Departamento de Física e Biofísica. Botucatu, SP, Brasil.Fundação Oswaldo Cruz. Instituto Carlos Chagas. Curitiba, PR, Brasil.Instituto Butantan. Laboratório Especial de Ciclo Celular. São Paulo, SP, Brasil. / Instituto Butantan. Center of Toxins. Immune Response and Cell Signaling—CeTICS. São Paulo, SP, Brazil.Universidade Estadual Paulista Júlio de Mesquita Filho. Instituto de Biociências. Departamento de Física e Biofísica. Botucatu, SP, Brasil.Instituto Butantan. Center of Toxins. Immune Response and Cell Signaling—CeTICS. São Paulo, SP, Brazil / Instituto Butantan. Laboratório de Imunoquímica. São Paulo, SP, Brasil.Universidade Federal de Minas Gerais. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, Brasil.Universidade Estadual Paulista Julio Mesquita Filho. Instituto de Biociências. Departamento de Genética. Botucatu, SP, Brasil.Replication Protein A (RPA), the major single stranded DNA binding protein in eukaryotes, is composed of three subunits and is a fundamental player in DNA metabolism, participating in replication, transcription, repair, and the DNA damage response. In human pathogenic trypanosomatids, only limited studies have been performed on RPA-1 from Leishmania. Here, we performed in silico, in vitro and in vivo analysis of Trypanosoma cruzi RPA-1 and RPA-2 subunits. Although computational analysis suggests similarities in DNA binding and Ob-fold structures of RPA from T. cruzi compared with mammalian and fungi RPA, the predicted tridimensional structures of T. cruzi RPA-1 and RPA-2 indicated that these molecules present a more flexible tertiary structure, suggesting that T. cruzi RPA could be involved in additional responses. Here, we demonstrate experimentally that the T. cruzi RPA complex interacts with DNA via RPA-1 and is directly related to canonical functions, such as DNA replication and DNA damage response. Accordingly, a reduction of TcRPA-2 expression by generating heterozygous knockout cells impaired cell growth, slowing down S-phase progression. Moreover, heterozygous knockout cells presented a better efficiency in differentiation from epimastigote to metacyclic trypomastigote forms and metacyclic trypomastigote infection. Taken together, these findings indicate the involvement of TcRPA in the metacyclogenesis process and suggest that a delay in cell cycle progression could be linked with differentiation in T. cruzi

The pattern of TcRPA distribution changes after DNA damage.

<p>Cells were treated with HU (A) or irradiated with UV (B). Cells were fixed, permeabilized and incubated with anti-rTcRPA-1 (anti-RPA-1), anti-rTcRPA-2 (anti-RPA-2) and anti-CPD and stained with DAPI. In A, the percentage of cells found with each pattern of RPA distribution is indicated.</p

Generation of heterozygous knockout cells expressing reduced levels of TcRPA-2.

<p>A. Schematic representation of the TcRPA-2 locus (central panel) or the locus generated after replacement of the RPA-2 gene by gene targeting (bottom panel) with the recombination cassette carrying the hygromycin resistance gene (top panel). Arrows indicate the regions where the primers used in the experiments presented in B anneal. B. DNA extracted from RPA-2 heterozygous knockout cells was amplified using the primers presented in A. 1- Hyg_f (2) + Hyg_r (3) (1.026 bp); 2- Hyg_f (2) + EXT5’_r (4) (2.113 bp); 3- EXT5’_f (1) + Hyg_r (3) (1.994 bp); 4- EXT5’_f (1) + EXT3’_r (4). 5–1 kb plus DNA ladder marker (Invitrogen). The primers EXT5’_f and EXT3’_r anneal in regions outside of the recombination site. Thus, the two bands observed in lane 4 correspond to the amplified regions from the wild-type (2.070 bp) and targeted RPA-2 alleles (3.081 bp), which are present in the RPA-2+/- parasites. C. Cell extracts from control and RPA-2+/- cells were subjected to SDS-PAGE, transferred onto nitrocellulose membranes and incubated with anti-rTcRPA-2 or anti-GAPDH, which was used as a loading control. D. The intensity of the bands obtained with anti-rTcRPA-2 presented on C were normalized using the intensity of the GAPDH bands. Graph shows average and standard deviation of three independents experiments.</p

TcRPA-1 and TcRPA-2 form a complex <i>in vivo</i> and localize at replication foci.

<p>A. Cell extracts were immunoprecipitated with an anti-rTcRPA-2 antibody (anti-RPA2) or with pre-immune serum as a control. Samples eluted from the resin were submitted to SDS-PAGE, transferred onto nitrocellulose membranes and incubated with anti-rTcRPA-1 (anti-RPA-1) or anti-rTcRPA-2 (anti-RPA-2) antibodies. B. Cells were incubated with EdU, fixed, incubated with anti-rTcRPA-1 (anti-RPA-1) or anti-rTcRPA-2 (anti-RPA-2) and stained with DAPI. N-nucleus, k-kinetoplast.</p

TcRPA-1 is able to bind ssDNA by OBF1.

<p>A and B. Circular dichroism (CD) spectra of (A) rTcRPA-1 and (B) rTcRPA-2 in the absence (black line) or presence of single stranded DNA of 24 bp (ssDNA24; blue line). A digoxin-labeled single stranded DNA (ssDNA) was maintained alone or in the presence (+) of recombinant TcRPA-1 (rRPA-1) (C) or of increasing concentrations of recombinant TcRPA-2 (rRPA-2) (D). The samples were analyzed by EMSA. E. Schematic representation of entire TcRPA-1 and three truncated mutants corresponding to each OBF domain. F. A digoxigenin-labeled ssDNA was maintained alone (-) or in the presence of recombinant OBF1, OBF2, and OBF3.</p

RPA-2 heterozygous knockout cells present growth and DNA replication impairment and S-phase progression delay.

<p>A. Growth curve of RPA-2+/- and wild type (wt) cells. * indicates the day during the growth curve that samples were taken to perform assays presented in B and C. B. Control and RPA-2+/- cells were maintained in the presence of EdU for 5 minutes and the percentage of labeled cells was determined. Graph shows average and standard deviation of three independents experiments. C. FACS analysis of wild type (wt) and RPA-2+/- cells labeled with propidium iodide. D. Growth culture of wild type (wt) and RPA-2+/- cells after treatment with 75μM of cisplatin or with no treatment (no drug). Statistical analyses were performed using a Student t-test, ** means p < 0.001; n.s. means p > 0.8.</p