Júlio Oliveira - Academia.edu (original) (raw)

Papers by Júlio Oliveira

Food and Chemical Toxicology, 2002

The ''sun mushroom'' is the popular name for the Agaricus blazei Murill fungus, a mushroom native... more The ''sun mushroom'' is the popular name for the Agaricus blazei Murill fungus, a mushroom native to south-eastern Brazil, which has been frequently used in popular medicine mainly in the form of tea to treat various ailments (stress, diabetes, etc.). In the present study, the genotoxic and/or anti-genotoxic effects ofA. blazei on mammalian cells in culture was assessed by checking the increase or reduction of micronucleus (MN) frequency and comets. The sun mushroom (lineage 99/26) was used as aqueous extracts prepared (2.5%) at three different temperatures (60, 25 and 4 C). The in vitro micronucleus (MN) test in binucleated cells and comet assay were used in V79 cells cultivated in HAM-F10+DMEM medium (1:1), supplemented with 10% of fetal bovine serum. The experiments were divided into four treatment types: 1. Negative control; 2. Positive control with MMS; 3. Treatments with the three forms of extracts (60, 25 and 4 C); and 4. Treatments with the extracts in different associations (simultaneous, pre-treatment, post-treatment and simultaneous after pre-incubation for 1 h) with MMS. None of the A. blazei extracts show genotoxic activity. In the comet assay no protecting effect was found. The results obtained in the MN test showed that the three forms of extracts used had protective activity, suggesting that the compound or active ingredients of A. blazei are always present in these extracts. The greater protective efficiency of the simultaneous treatment and simultaneous treatment with pre-incubation mixture with MMS suggests that the extracts have an antimutagenic action of the desmutagenic type. #

Scientia Agricola, 2006

Soil water content (q) and bulk density (rs) greatly influence important soil and plant processes... more Soil water content (q) and bulk density (rs) greatly influence important soil and plant processes, such as water movement, soil compaction, soil aeration, and plant root system development. Spatial and temporal variability of q and rs during different periods of the year and different phases of crops are of fundamental interest. This work involves the characterization of spatial and temporal patterns of q and rs during different climatic periods of year, aiming to verify whether there are significant temporal changes in rs at the soil surface layer when submitted to wetting and drying cycles. The field experiment was carried out in a coffee plantation, Rhodic Kandiudalf soil, clayey texture. Using a neutron/gamma surface probe, q and rs were measured meter by meter along a 200 m spatial transect, along an interrow contour line. During the wet period there was no difference of spatial patterns of q while during the dry period differences were observed, and can be associated to precipitation events. It was also observed that there are rs temporal changes at the soil surface along the studied period as a consequence of the in situ wetting and drying cycles.

Australian Journal of Soil Research, 2005

Among the methods used to measure soil bulk density, the following have been prominent: paraffin ... more Among the methods used to measure soil bulk density, the following have been prominent: paraffin sealed clod (PS), volumetric ring (VR), and the modern methods like gamma ray computed tomography (GCT) and the neutron/gamma surface gauge (SG). The objective of this work was to compare soil bulk density values obtained through these methods, with the aim of assisting researchers on the choice of the more appropriate method. For this, a 200 m spatial transect was chosen in an experimental area cultivated with coffee belonging to ESALQ/USP, Piracicaba, SP, Brazil. The SG readings were first taken in the field and thereafter soil samples were collected at 8 different points, spaced at 25 m, for the other methods. The lowest values of soil bulk density were obtained for the SG method (average 1.468 g/cm 3 ) and the highest for the PS (average 1.685 g/cm 3 ), which was similar to the GCT method (average 1.684 g/cm 3 ).

Scientia Agricola, 1997

A neutron probe calibration correction is proposed in order to reduce soil water content variabil... more A neutron probe calibration correction is proposed in order to reduce soil water content variability, assumed to be a consequence of improper calibrations relations. The time stability of spatially measured soil water content data is used to correct the intercepts of linear calibration relations. This procedure reduced the coefficients of variation of soil water content data from 4 to less than 2% in a Rhodic Kanhapludalf.

Scientia Agricola, 2000

Results of an organic matter management experiment of a sugar cane crop are reported for the firs... more Results of an organic matter management experiment of a sugar cane crop are reported for the first cropping year. Sugar cane was planted in October 1997, and labeled with a 15 N fertilizer pulse to study the fate of organic matter in the soil-plant system. A nitrogen balance is presented, partitioning the system in plant components (stalk, tip and straw), soil components (five soil organic matter fractions) and evaluating leaching losses. The 15 N label permitted to determine, at the end of the growing season, amounts of nitrogen derived from the fertilizer, present in the above mentioned compartments.

Soil & Tillage Research, 1998

The determination and the use of soil hydraulic conductivity functions obtained from internal dra... more The determination and the use of soil hydraulic conductivity functions obtained from internal drainage experiments, performed in ®eld soil pro®les, using the Darcy±Buckingham¯ux gradient approach are discussed. Details of the calculation procedures indicate the sensitivity of the methodologies used, and of the most commonly adopted model for K() relations: K()K 0 .exp[À.( 0 À)]. It is shown that the unit total water potential gradient cannot prevail in the whole soil pro®le during internal drainage after in®ltration and that, as a consequence of this assumption, several methods of hydraulic conductivity determination yield K() relations which are depth dependent, even for homogeneous soils. The dif®culties of using K() relations in modeling soil water dynamics due to their very strong exponential behaviour are also discussed. #

BMC Microbiology, 2009

Background Citrus canker is a disease caused by the phytopathogens Xanthomonas citri subsp. citri... more Background Citrus canker is a disease caused by the phytopathogens Xanthomonas citri subsp. citri, Xanthomonas fuscans subsp. aurantifolli and Xanthomonas alfalfae subsp. citrumelonis. The first of the three species, which causes citrus bacterial canker type A, is the most widely spread and severe, attacking all citrus species. In Brazil, this species is the most important, being found in practically all areas where citrus canker has been detected. Like most phytobacterioses, there is no efficient way to control citrus canker. Considering the importance of the disease worldwide, investigation is needed to accurately detect which genes are related to the pathogen-host adaptation process and which are associated with pathogenesis. Results Through transposon insertion mutagenesis, 10,000 mutants of Xanthomonas citri subsp. citri strain 306 (Xcc) were obtained, and 3,300 were inoculated in Rangpur lime (Citrus limonia) leaves. Their ability to cause citrus canker was analyzed every 3 days until 21 days after inoculation; a set of 44 mutants showed altered virulence, with 8 presenting a complete loss of causing citrus canker symptoms. Sequencing of the insertion site in all 44 mutants revealed that 35 different ORFs were hit, since some ORFs were hit in more than one mutant, with mutants for the same ORF presenting the same phenotype. An analysis of these ORFs showed that some encoded genes were previously known as related to pathogeniCity in phytobacteria and, more interestingly, revealed new genes never implicated with Xanthomonas pathogeniCity before, including hypothetical ORFs. Among the 8 mutants with no canker symptoms are the hrpB4 and hrpX genes, two genes that belong to type III secretion system (TTSS), two hypothetical ORFS and, surprisingly, the htrA gene, a gene reported as involved with the virulence process in animal-pathogenic bacteria but not described as involved in phytobacteria virulence. Nucleic acid hybridization using labeled cDNA probes showed that some of the mutated genes are differentially expressed when the bacterium is grown in citrus leaves. Finally, comparative genomic analysis revealed that 5 mutated ORFs are in new putative pathogeniCity islands. Conclusion The identification of these new genes related with Xcc infection and virulence is a great step towards the understanding of plant-pathogen interactions and could allow the development of strategies to control citrus canker.

Geoderma, 2003

The present study's objectives were to quantify the fertilizer-N and residue-N balances of a suga... more The present study's objectives were to quantify the fertilizer-N and residue-N balances of a sugar cane crop under two trash management systems. The fate of nitrogen (N) derived from fertilizer (NdfF) and N derived from residue (NdfR) was studied comparing: (i) the traditional harvest system with trash burning before harvest (''trash burning'') and (ii) an alternative system without trash burning, in which crop residues are left on the soil surface (''trash mulching''). The experiment consisted of three treatments: (i) T1: at planting, the sugarcane crop was fertilized with 63 kg N ha À 1 as 15 N-labeled ammonium sulfate, and after the 1st harvest received unlabeled trash from T2; (ii) T2: at planting, the crop was fertilized with 63 kg N ha À 1 as unlabeled ammonium sulfate. At the 1st harvest time, this treatment received the labeled trash from T1; (iii) T3: at planting, the crop was fertilized with 63 kg N ha À 1 as 15 N-labeled ammonium sulfate, and every year, immediately before cutting, the crop residues were burnt. After the first harvest fertilizer-N was applied over the total soil area at a rate of 80 kg N ha À 1 as unlabeled ammonium sulfate. The results indicated that the trash remaining as a surface blanket resulted in an average N recycling of 105.0 kg ha À 1 year À 1 , while the practice of burning the trash produced an average N loss from the system of 83.5 kg ha À 1 year À 1 . At the first harvest, about 75% of the labeled N was recovered in the soil -plant system. The majority was found in the plant, indicating a high availability of the fertilizer-N for the crop. At the end of the third crop cycle (2nd ratoon crop harvest), the total output of fertilizer-N (export + burning) was 60% for the burnt-trash treatment, and only 42% (export) for the trash-blanket treatment. The N liberated from the residue is mainly immobilized in the soil, reflecting that sugarcane trash is an N source of slow availability to the crop. This study indicated that green cane harvesting followed by mulching 0016-7061/03/$ -see front matter D (M.V. Basanta).

Scientia Agricola, 2006

Establishing field water balances is difficult and costly, the variability of their components be... more Establishing field water balances is difficult and costly, the variability of their components being the major problem to obtain reliable results. This component variability is presented herein for a coffee crop grown in the Southern Hemisphere, on a tropical soil with 10% slope. It was observed that: rainfall has to be measured with an appropriate number of replicates; irrigation can introduce great variability into calculations; evapotranspiration, calculated as a remainder of the water balance equation, has exceedingly high coefficients of variation; the soil water storage component is the major contributor in error propagation calculations to estimate evapotranspiration; and that runoff can be satisfactorily controlled on the 10% slope through crop management practices.

Scientia Agricola, 1998

ABSTRACT

Scientia Agricola, 1999

The state-space approach is used to describe surface soil water content and temperature behaviour... more The state-space approach is used to describe surface soil water content and temperature behaviour, in a field experiment in which sugarcane is submitted to different management practices. The treatments consisted of harvest trash mulching, bare soil, and burned trash, all three in a ratoon crop, after first cane harvest. One transect of 84 points was sampled, meter by meter, covering all treatments and borders. The state-space approach is described in detail and the results show that soil water contents measured along the transect could successfully be estimated from water content and temperature observations made at the first neighbour.

Soil Science Society of America Journal, 1997

ABSTRACT The size distribution of particles is useful for physical characterization of soil. This... more ABSTRACT The size distribution of particles is useful for physical characterization of soil. This study was conducted to determine whether a new method of soil particle-size analysis by gamma-ray attenuation could be further improved by changing the depth and time of ...

Molecular Plant-microbe Interactions, 2000

Colletotrichum lindemuthianum. A "candidate gene" approach was used to map anthracnose resistance... more Colletotrichum lindemuthianum. A "candidate gene" approach was used to map anthracnose resistance quantitative trait loci (QTL). Candidate genes included genes for both pathogen recognition (resistance genes and resistance gene analogs [RGAs]) and general plant defense (defense response genes). Two strains of C. lindemuthianum, identified in a world collection of 177 strains, displayed a reproducible and differential aggressiveness toward BAT93 and JaloEEP558, two parental lines of P. vulgaris representing the two major gene pools of this crop. A reliable test was developed to score partial resistance in aerial organs of the plant (stem, leaf, petiole) under controlled growth chamber conditions. BAT93 was more resistant than Jalo-EEP558 regardless of the organ or strain tested. With a recombinant inbred line (RIL) population derived from a cross between these two parental lines, 10 QTL were located on a genetic map harboring 143 markers, including known defense response genes, anthracnose-specific resistance genes, and RGAs. Eight of the QTL displayed isolate specificity. Two were co-localized with known defense genes (phenylalanine ammonia-lyase and hydroxyprolinerich glycoprotein) and three with anthracnose-specific resistance genes and/or RGAs. Interestingly, two QTL, with different allelic contribution, mapped on linkage group B4 in a 5.0 cM interval containing Andean and Mesoamerican specific resistance genes against C. lindemuthianum and 11 polymorphic fragments revealed with a RGA probe. The possible relationship between genes underlying specific and partial resistance is discussed.

Molecular Plant-microbe Interactions, 1999

The recent cloning of plant resistance (R) genes and the sequencing of resistance gene clusters h... more The recent cloning of plant resistance (R) genes and the sequencing of resistance gene clusters have shed light on the molecular evolution of R genes. However, up to now, no attempt has been made to correlate this molecular evolution with the host-pathogen coevolution process at the population level. Cross-inoculations were carried out between 26 strains of the fungal pathogen Colletotrichum lindemuthianum and 48 Phaseolus vulgaris plants collected in the three centers of diversity of the host species. A high level of diversity for resistance against the pathogen was revealed. Most of the resistance specificities were overcome in sympatric situations, indicating an adaptation of the pathogen to the local host. In contrast, plants were generally resistant to allopatric strains, suggesting that R genes that were efficient against exotic strains but had been overcome locally were maintained in the plant genome. These results indicated that coevolution processes between the two protagonists led to a differentiation for resistance in the three centers of diversity of the host. To improve our understanding of the molecular evolution of these different specificities, a recombinant inbred (RI) population derived from two representative genotypes of the Andean (JaloEEP558) and Mesoamerican (BAT93) gene pools was used to map anthracnose specificities. A gene cluster comprising both Andean (Co-y; Co-z) and Mesoamerican (Co-9) host resistance specificities was identified, suggesting that this locus existed prior to the separation of the two major gene pools of P. vulgaris. Molecular analysis revealed a high level of complexity at this locus. It harbors 11 restriction fragment length polymor-phisms when R gene analog (RGA) clones are used. The relationship between the coevolution process and diversification of resistance specificities at resistance gene clusters is discussed.

Resuscitation, 2003

We present a case report of successful treatment of shock induced by the calcium channel blocker ... more We present a case report of successful treatment of shock induced by the calcium channel blocker (CCB) diltiazem. A 75-year-old woman took a combination of tablets, including diltiazem. Soon after arrival, she developed haemodynamic shock which persisted despite treatment with fluids, dopamine, dobutamine, norepinephrine (noradrenaline), calcium gluconate and glucagon. Haemodynamic stability was not achieved until an insulin infusion and glucose administration was started. We review the literature and the updated guidelines for the treatment of CCB intoxication, with particular emphasis on situations where insulin and glucose infusions can be live saving.

European Journal of Biochemistry, 1994

We have isolated and characterized cDNA and genomic DNA clones encoding the catalytic subunit (C)... more We have isolated and characterized cDNA and genomic DNA clones encoding the catalytic subunit (C) of CAMP-dependent protein kinase in the aquatic fungus Blastocladiella emersonii. The C-subunit amino acid sequence derived from the nucleotide sequence predicts a basic polypeptide of 424 residues, excluding the initiator methionine, which by amino-terminal sequence analysis has been shown to be absent from the mature protein. The Blastocladiella C presents a 70-amino-acid extension at the amino terminus, when aligned to the mouse Ca subunit, being one of the largest C subunits already characterized. The B. emersonii C-gene-coding region is interrupted by three introns, ranging in size over 57-69 bp. The positions of the introns are quite different from those found in other species, suggesting a considerable amount of evolutionary drift in the gene structure. The 5'-flanking region lacks recognizable TATA or CCAAT sequences, is remarkably high in GC content (70%), and primer extension experiments indicate that transcription initiates from multiple sites. Several sequence motifs were identified in the promoter region which could be involved in the developmental control of this gene.

Food and Chemical Toxicology, 2002

The ''sun mushroom'' is the popular name for the Agaricus blazei Murill fungus, a mushroom native... more The ''sun mushroom'' is the popular name for the Agaricus blazei Murill fungus, a mushroom native to south-eastern Brazil, which has been frequently used in popular medicine mainly in the form of tea to treat various ailments (stress, diabetes, etc.). In the present study, the genotoxic and/or anti-genotoxic effects ofA. blazei on mammalian cells in culture was assessed by checking the increase or reduction of micronucleus (MN) frequency and comets. The sun mushroom (lineage 99/26) was used as aqueous extracts prepared (2.5%) at three different temperatures (60, 25 and 4 C). The in vitro micronucleus (MN) test in binucleated cells and comet assay were used in V79 cells cultivated in HAM-F10+DMEM medium (1:1), supplemented with 10% of fetal bovine serum. The experiments were divided into four treatment types: 1. Negative control; 2. Positive control with MMS; 3. Treatments with the three forms of extracts (60, 25 and 4 C); and 4. Treatments with the extracts in different associations (simultaneous, pre-treatment, post-treatment and simultaneous after pre-incubation for 1 h) with MMS. None of the A. blazei extracts show genotoxic activity. In the comet assay no protecting effect was found. The results obtained in the MN test showed that the three forms of extracts used had protective activity, suggesting that the compound or active ingredients of A. blazei are always present in these extracts. The greater protective efficiency of the simultaneous treatment and simultaneous treatment with pre-incubation mixture with MMS suggests that the extracts have an antimutagenic action of the desmutagenic type. #

Scientia Agricola, 2006

Soil water content (q) and bulk density (rs) greatly influence important soil and plant processes... more Soil water content (q) and bulk density (rs) greatly influence important soil and plant processes, such as water movement, soil compaction, soil aeration, and plant root system development. Spatial and temporal variability of q and rs during different periods of the year and different phases of crops are of fundamental interest. This work involves the characterization of spatial and temporal patterns of q and rs during different climatic periods of year, aiming to verify whether there are significant temporal changes in rs at the soil surface layer when submitted to wetting and drying cycles. The field experiment was carried out in a coffee plantation, Rhodic Kandiudalf soil, clayey texture. Using a neutron/gamma surface probe, q and rs were measured meter by meter along a 200 m spatial transect, along an interrow contour line. During the wet period there was no difference of spatial patterns of q while during the dry period differences were observed, and can be associated to precipitation events. It was also observed that there are rs temporal changes at the soil surface along the studied period as a consequence of the in situ wetting and drying cycles.

Australian Journal of Soil Research, 2005

Among the methods used to measure soil bulk density, the following have been prominent: paraffin ... more Among the methods used to measure soil bulk density, the following have been prominent: paraffin sealed clod (PS), volumetric ring (VR), and the modern methods like gamma ray computed tomography (GCT) and the neutron/gamma surface gauge (SG). The objective of this work was to compare soil bulk density values obtained through these methods, with the aim of assisting researchers on the choice of the more appropriate method. For this, a 200 m spatial transect was chosen in an experimental area cultivated with coffee belonging to ESALQ/USP, Piracicaba, SP, Brazil. The SG readings were first taken in the field and thereafter soil samples were collected at 8 different points, spaced at 25 m, for the other methods. The lowest values of soil bulk density were obtained for the SG method (average 1.468 g/cm 3 ) and the highest for the PS (average 1.685 g/cm 3 ), which was similar to the GCT method (average 1.684 g/cm 3 ).

Scientia Agricola, 1997

A neutron probe calibration correction is proposed in order to reduce soil water content variabil... more A neutron probe calibration correction is proposed in order to reduce soil water content variability, assumed to be a consequence of improper calibrations relations. The time stability of spatially measured soil water content data is used to correct the intercepts of linear calibration relations. This procedure reduced the coefficients of variation of soil water content data from 4 to less than 2% in a Rhodic Kanhapludalf.

Scientia Agricola, 2000

Results of an organic matter management experiment of a sugar cane crop are reported for the firs... more Results of an organic matter management experiment of a sugar cane crop are reported for the first cropping year. Sugar cane was planted in October 1997, and labeled with a 15 N fertilizer pulse to study the fate of organic matter in the soil-plant system. A nitrogen balance is presented, partitioning the system in plant components (stalk, tip and straw), soil components (five soil organic matter fractions) and evaluating leaching losses. The 15 N label permitted to determine, at the end of the growing season, amounts of nitrogen derived from the fertilizer, present in the above mentioned compartments.

Soil & Tillage Research, 1998

The determination and the use of soil hydraulic conductivity functions obtained from internal dra... more The determination and the use of soil hydraulic conductivity functions obtained from internal drainage experiments, performed in ®eld soil pro®les, using the Darcy±Buckingham¯ux gradient approach are discussed. Details of the calculation procedures indicate the sensitivity of the methodologies used, and of the most commonly adopted model for K() relations: K()K 0 .exp[À.( 0 À)]. It is shown that the unit total water potential gradient cannot prevail in the whole soil pro®le during internal drainage after in®ltration and that, as a consequence of this assumption, several methods of hydraulic conductivity determination yield K() relations which are depth dependent, even for homogeneous soils. The dif®culties of using K() relations in modeling soil water dynamics due to their very strong exponential behaviour are also discussed. #

BMC Microbiology, 2009

Background Citrus canker is a disease caused by the phytopathogens Xanthomonas citri subsp. citri... more Background Citrus canker is a disease caused by the phytopathogens Xanthomonas citri subsp. citri, Xanthomonas fuscans subsp. aurantifolli and Xanthomonas alfalfae subsp. citrumelonis. The first of the three species, which causes citrus bacterial canker type A, is the most widely spread and severe, attacking all citrus species. In Brazil, this species is the most important, being found in practically all areas where citrus canker has been detected. Like most phytobacterioses, there is no efficient way to control citrus canker. Considering the importance of the disease worldwide, investigation is needed to accurately detect which genes are related to the pathogen-host adaptation process and which are associated with pathogenesis. Results Through transposon insertion mutagenesis, 10,000 mutants of Xanthomonas citri subsp. citri strain 306 (Xcc) were obtained, and 3,300 were inoculated in Rangpur lime (Citrus limonia) leaves. Their ability to cause citrus canker was analyzed every 3 days until 21 days after inoculation; a set of 44 mutants showed altered virulence, with 8 presenting a complete loss of causing citrus canker symptoms. Sequencing of the insertion site in all 44 mutants revealed that 35 different ORFs were hit, since some ORFs were hit in more than one mutant, with mutants for the same ORF presenting the same phenotype. An analysis of these ORFs showed that some encoded genes were previously known as related to pathogeniCity in phytobacteria and, more interestingly, revealed new genes never implicated with Xanthomonas pathogeniCity before, including hypothetical ORFs. Among the 8 mutants with no canker symptoms are the hrpB4 and hrpX genes, two genes that belong to type III secretion system (TTSS), two hypothetical ORFS and, surprisingly, the htrA gene, a gene reported as involved with the virulence process in animal-pathogenic bacteria but not described as involved in phytobacteria virulence. Nucleic acid hybridization using labeled cDNA probes showed that some of the mutated genes are differentially expressed when the bacterium is grown in citrus leaves. Finally, comparative genomic analysis revealed that 5 mutated ORFs are in new putative pathogeniCity islands. Conclusion The identification of these new genes related with Xcc infection and virulence is a great step towards the understanding of plant-pathogen interactions and could allow the development of strategies to control citrus canker.

Geoderma, 2003

The present study's objectives were to quantify the fertilizer-N and residue-N balances of a suga... more The present study's objectives were to quantify the fertilizer-N and residue-N balances of a sugar cane crop under two trash management systems. The fate of nitrogen (N) derived from fertilizer (NdfF) and N derived from residue (NdfR) was studied comparing: (i) the traditional harvest system with trash burning before harvest (''trash burning'') and (ii) an alternative system without trash burning, in which crop residues are left on the soil surface (''trash mulching''). The experiment consisted of three treatments: (i) T1: at planting, the sugarcane crop was fertilized with 63 kg N ha À 1 as 15 N-labeled ammonium sulfate, and after the 1st harvest received unlabeled trash from T2; (ii) T2: at planting, the crop was fertilized with 63 kg N ha À 1 as unlabeled ammonium sulfate. At the 1st harvest time, this treatment received the labeled trash from T1; (iii) T3: at planting, the crop was fertilized with 63 kg N ha À 1 as 15 N-labeled ammonium sulfate, and every year, immediately before cutting, the crop residues were burnt. After the first harvest fertilizer-N was applied over the total soil area at a rate of 80 kg N ha À 1 as unlabeled ammonium sulfate. The results indicated that the trash remaining as a surface blanket resulted in an average N recycling of 105.0 kg ha À 1 year À 1 , while the practice of burning the trash produced an average N loss from the system of 83.5 kg ha À 1 year À 1 . At the first harvest, about 75% of the labeled N was recovered in the soil -plant system. The majority was found in the plant, indicating a high availability of the fertilizer-N for the crop. At the end of the third crop cycle (2nd ratoon crop harvest), the total output of fertilizer-N (export + burning) was 60% for the burnt-trash treatment, and only 42% (export) for the trash-blanket treatment. The N liberated from the residue is mainly immobilized in the soil, reflecting that sugarcane trash is an N source of slow availability to the crop. This study indicated that green cane harvesting followed by mulching 0016-7061/03/$ -see front matter D (M.V. Basanta).

Scientia Agricola, 2006

Establishing field water balances is difficult and costly, the variability of their components be... more Establishing field water balances is difficult and costly, the variability of their components being the major problem to obtain reliable results. This component variability is presented herein for a coffee crop grown in the Southern Hemisphere, on a tropical soil with 10% slope. It was observed that: rainfall has to be measured with an appropriate number of replicates; irrigation can introduce great variability into calculations; evapotranspiration, calculated as a remainder of the water balance equation, has exceedingly high coefficients of variation; the soil water storage component is the major contributor in error propagation calculations to estimate evapotranspiration; and that runoff can be satisfactorily controlled on the 10% slope through crop management practices.

Scientia Agricola, 1998

ABSTRACT

Scientia Agricola, 1999

The state-space approach is used to describe surface soil water content and temperature behaviour... more The state-space approach is used to describe surface soil water content and temperature behaviour, in a field experiment in which sugarcane is submitted to different management practices. The treatments consisted of harvest trash mulching, bare soil, and burned trash, all three in a ratoon crop, after first cane harvest. One transect of 84 points was sampled, meter by meter, covering all treatments and borders. The state-space approach is described in detail and the results show that soil water contents measured along the transect could successfully be estimated from water content and temperature observations made at the first neighbour.

Soil Science Society of America Journal, 1997

ABSTRACT The size distribution of particles is useful for physical characterization of soil. This... more ABSTRACT The size distribution of particles is useful for physical characterization of soil. This study was conducted to determine whether a new method of soil particle-size analysis by gamma-ray attenuation could be further improved by changing the depth and time of ...

Molecular Plant-microbe Interactions, 2000

Colletotrichum lindemuthianum. A "candidate gene" approach was used to map anthracnose resistance... more Colletotrichum lindemuthianum. A "candidate gene" approach was used to map anthracnose resistance quantitative trait loci (QTL). Candidate genes included genes for both pathogen recognition (resistance genes and resistance gene analogs [RGAs]) and general plant defense (defense response genes). Two strains of C. lindemuthianum, identified in a world collection of 177 strains, displayed a reproducible and differential aggressiveness toward BAT93 and JaloEEP558, two parental lines of P. vulgaris representing the two major gene pools of this crop. A reliable test was developed to score partial resistance in aerial organs of the plant (stem, leaf, petiole) under controlled growth chamber conditions. BAT93 was more resistant than Jalo-EEP558 regardless of the organ or strain tested. With a recombinant inbred line (RIL) population derived from a cross between these two parental lines, 10 QTL were located on a genetic map harboring 143 markers, including known defense response genes, anthracnose-specific resistance genes, and RGAs. Eight of the QTL displayed isolate specificity. Two were co-localized with known defense genes (phenylalanine ammonia-lyase and hydroxyprolinerich glycoprotein) and three with anthracnose-specific resistance genes and/or RGAs. Interestingly, two QTL, with different allelic contribution, mapped on linkage group B4 in a 5.0 cM interval containing Andean and Mesoamerican specific resistance genes against C. lindemuthianum and 11 polymorphic fragments revealed with a RGA probe. The possible relationship between genes underlying specific and partial resistance is discussed.

Molecular Plant-microbe Interactions, 1999

The recent cloning of plant resistance (R) genes and the sequencing of resistance gene clusters h... more The recent cloning of plant resistance (R) genes and the sequencing of resistance gene clusters have shed light on the molecular evolution of R genes. However, up to now, no attempt has been made to correlate this molecular evolution with the host-pathogen coevolution process at the population level. Cross-inoculations were carried out between 26 strains of the fungal pathogen Colletotrichum lindemuthianum and 48 Phaseolus vulgaris plants collected in the three centers of diversity of the host species. A high level of diversity for resistance against the pathogen was revealed. Most of the resistance specificities were overcome in sympatric situations, indicating an adaptation of the pathogen to the local host. In contrast, plants were generally resistant to allopatric strains, suggesting that R genes that were efficient against exotic strains but had been overcome locally were maintained in the plant genome. These results indicated that coevolution processes between the two protagonists led to a differentiation for resistance in the three centers of diversity of the host. To improve our understanding of the molecular evolution of these different specificities, a recombinant inbred (RI) population derived from two representative genotypes of the Andean (JaloEEP558) and Mesoamerican (BAT93) gene pools was used to map anthracnose specificities. A gene cluster comprising both Andean (Co-y; Co-z) and Mesoamerican (Co-9) host resistance specificities was identified, suggesting that this locus existed prior to the separation of the two major gene pools of P. vulgaris. Molecular analysis revealed a high level of complexity at this locus. It harbors 11 restriction fragment length polymor-phisms when R gene analog (RGA) clones are used. The relationship between the coevolution process and diversification of resistance specificities at resistance gene clusters is discussed.

Resuscitation, 2003

We present a case report of successful treatment of shock induced by the calcium channel blocker ... more We present a case report of successful treatment of shock induced by the calcium channel blocker (CCB) diltiazem. A 75-year-old woman took a combination of tablets, including diltiazem. Soon after arrival, she developed haemodynamic shock which persisted despite treatment with fluids, dopamine, dobutamine, norepinephrine (noradrenaline), calcium gluconate and glucagon. Haemodynamic stability was not achieved until an insulin infusion and glucose administration was started. We review the literature and the updated guidelines for the treatment of CCB intoxication, with particular emphasis on situations where insulin and glucose infusions can be live saving.

European Journal of Biochemistry, 1994

We have isolated and characterized cDNA and genomic DNA clones encoding the catalytic subunit (C)... more We have isolated and characterized cDNA and genomic DNA clones encoding the catalytic subunit (C) of CAMP-dependent protein kinase in the aquatic fungus Blastocladiella emersonii. The C-subunit amino acid sequence derived from the nucleotide sequence predicts a basic polypeptide of 424 residues, excluding the initiator methionine, which by amino-terminal sequence analysis has been shown to be absent from the mature protein. The Blastocladiella C presents a 70-amino-acid extension at the amino terminus, when aligned to the mouse Ca subunit, being one of the largest C subunits already characterized. The B. emersonii C-gene-coding region is interrupted by three introns, ranging in size over 57-69 bp. The positions of the introns are quite different from those found in other species, suggesting a considerable amount of evolutionary drift in the gene structure. The 5'-flanking region lacks recognizable TATA or CCAAT sequences, is remarkably high in GC content (70%), and primer extension experiments indicate that transcription initiates from multiple sites. Several sequence motifs were identified in the promoter region which could be involved in the developmental control of this gene.