Sergio Roberto - Academia.edu (original) (raw)

Papers by Sergio Roberto

The remainder of the six years of privatization and denationalization of Colombia Telecommunicati... more The remainder of the six years of privatization and denationalization of Colombia Telecommunications, has been a negative factor for Colombia and its citizens. The new foreign operator, Telefonica Internacional, failed to comply with its contractual obligations, its management and service are terrible, its financial results are negative and fur - thermore it has been saved by the Law on Capitalization, a government initiative, approved by the president of the Republic, thereby converting the Nation of Colombia into the custodian of oligopolistic transnational interests. Its nationalization will allow it to recover and to protect public patrimony, place it at the service of economic develop- ment, social progress and the well being of Colombians. The research undertaken has integrated historical and logic methodology, making use of primary sources such as interviews, laws, decrees, reports, opinions and judgments as well as secondary sources such as theses, assays and articles in add...

The Technologies of information and Communication (TIC), divides the microelectronics world into ... more The Technologies of information and Communication (TIC), divides the microelectronics world into computer science and telecommunications and they constitute a new technological revolution. In it for the first time, the backbone is the information and not the energy.

Diálogos de saberes, 2015

Los servicios públicos domiciliarios constituyen una categoría especial de los servicios públicos... more Los servicios públicos domiciliarios constituyen una categoría especial de los servicios públicos. Son bienes insustituibles, necesidades esenciales de la población ligadas a la existencia, calidad y dignidad de la vida humana y, en consecuencia, derechos fundamentales. Son una actividad económica. En este trabajo se cuestiona el modelo colombiano de prestación, regulación y control. Se utiliza un enfoque socio jurídico e interdisciplinario, un método teórico (análisis y síntesis) y se hace análisis documental.

Diálogos de saberes, 2013

La Teoría del Servicio Público desde sus orígenes en Francia en la segunda mitad del siglo XIX ha... more La Teoría del Servicio Público desde sus orígenes en Francia en la segunda mitad del siglo XIX hasta nuestros días, ha tenido una importante influencia en Colombia y en el mundo occidental. Se analizan sus orígenes, su naturaleza, evolución y vigencia, sus tendencias y sus contradicciones actuales, su práctica en el contexto internacional de las transformaciones ideológicas, políticas y económicas de las últimas tres décadas y su aplicación actual en las telecomunicaciones. Los elementos democráticos de la teoría del Servicio Público recobran vigencia para el rescate de lo público, de la prestación directa delos servicios públicos esenciales por parte del Estado, la utilización del derecho administrativo y la jurisdicción contencioso administrativa para resolver sus conflictos y como alternativa a las concepciones privatistas y mercantilistas predominantes. En la parte correspondiente de la investigación realizada, se integraron los métodos histórico y lógico, el análisis y la sínte...

Horticulturae, 2018

'BRS Vitoria' (Vitis spp.) is a novel hybrid seedless table grape recommended for cultivation in ... more 'BRS Vitoria' (Vitis spp.) is a novel hybrid seedless table grape recommended for cultivation in tropical and subtropical areas, especially for overseas export. The main postharvest disease of this cultivar is botrytis or gray mold (Botrytis cinerea), which occurs even under low temperatures in cold chambers. Sulfur dioxide (SO 2) release pads have been used to control this disease under cold storage, but some grape cultivars are sensitive to certain levels of this compound. The objective of this work was to evaluate different types of SO 2 generator pads in order to prevent the incidence of gray mold of 'BRS Vitoria' seedless grape, as well to avoid other grape injuries during cold storage. Grape bunches were harvested when fully ripened (16 • Brix) from a commercial field trained on overhead trellis and located at Marialva, state of Parana (PR) (South Brazil). Grapes were packed into carton boxes and subjected to the following SO 2 pad treatments (Uvasys ® , Cape Town, South Africa) in a cold chamber (2 • C): (a) control; (b) SO 2 slow release pad; (c) SO 2 dual release pad; (d) SO 2 dual release-fast reduced pad; (e) SO 2 slow release pad with grapes inoculated with B. cinerea; (f) SO 2 dual release pad with grapes inoculated with B. cinerea; and (g) SO 2 dual release-fast reduced pad with grapes inoculated with B. cinerea. After a 50-day cold chamber period, the grape boxes were kept for 7 days at room temperature at 25 • C. A randomized design was used with seven treatments and four replications, with five bunches per plot. The incidence of gray mold on grapes was evaluated after the 50-day cold storage and after the 7-days-at-room-temperature periods, as well other grape physicochemical variables, such as shattered berries, stem browning, bunch mass, bunch mass loss, skin color, soluble solids (SS), titratable acidity (TA), and SS/TA. The dual release pads were more efficient in preventing the incidence of gray mold and mass loss in 'BRS Vitoria' seedless grapes than the slow release pads in both storage periods. The incidence of shattered berries was lower when any type SO 2 pad was used during cold storage, and no effects were observed on stem browning, firmness, or berry skin color of 'BRS Vitoria' grapes.

Agronomy Science and Biotechnology, 2019

The objective of this work was to investigate the effect of the resistance inducer Acibenzolar-S-... more The objective of this work was to investigate the effect of the resistance inducer Acibenzolar-S-methyl (ASM), against Botrytis mold on table grapes in vitro and in vivo. To assess the effect of ASM on mycelial growth Botrytis cinerea, different concentrations (0.125, 0.25, 0.5, 1.0, 2.0 and 3% w:v) were tested. Treatments were set up in triplicate, in a completely randomized experimental design, and replicated twice. Results were expressed in minimum inhibitory concentrations and effective dose per 50% response of mycelial growth. Healthy table grapes (cvs. Italia and Benitaka) were harvested at full ripe to evaluate the ASM 1% effect against gray mold under artificial conditions. Bunches were split into two groups in order to perform two types of experiments (spray or immersion). For both trials, treated bunches were arranged in carton boxes and stored at 2±1 °C, for one month, followed by one week of shelf-life at 22±2 °C. In order to evaluate the ASM effect against gray mold und...

Agronomy Science and Biotechnology, 2018

Grape juices are blended in order to balance the organoleptic characteristics of juice, as well a... more Grape juices are blended in order to balance the organoleptic characteristics of juice, as well as to reduce off-season costs. The aim of this study was to evaluate the acceptance of consumers, through sensory analysis, of ‘Bordô’, ‘Niagara Rosada’, ‘BRS Nubia’ and ‘Isabel’ grape juices and their blends. The experiment was conducted during two periods. In the first, the grape juices analyzed were: ‘Niagara Rosada’ 100%, ‘Bordô’ 100%, ‘Isabel’ 100%, ‘Isabel’ 90% + ‘Bordô’ 10% and ‘Isabel’ 80% + ‘Bordô’ 20%. In the second, the following juices were evaluated: ‘Bordô’ 100%, ‘Niagara Rosada’ 100%, ‘Bordô’ 75% + ‘Niagara Rosada’ 25%, ‘Bordô’ 50% + ‘Niagara Rosada’ 50%, ‘Bordô’ 25% + ‘Niagara Rosada’ 75% and ‘BRS Nubia’ 100%. The juices were obtained by the ‘Welch’ process by steam entrainment. For the sensory evaluation, six tasters evaluated the following attributes in each period: color, aroma, flavor, body and overall acceptability, using a 7-point hedonic scale. The ‘Niagara Rosada’ ...

Agronomy, 2019

In colored table grapes, the anthocyanin contents are inhibited by the high temperature during ri... more In colored table grapes, the anthocyanin contents are inhibited by the high temperature during ripening and berries suffer a lack of skin color, thus affecting their market value. In order to overcome this issue, a research study was planned to evaluate the influence of (S)-cis-abscisic acid (S-ABA) on rates of anthocyanin accumulation in table grapes when applied at different timings of ripening, and to quantify the gradual increase of berry color. The study was conducted in a commercial vineyard of ‘Benitaka’ table grapes (Vitis vinifera L.), grown under double annual cropping system in a subtropical area. The trials were carried out during two consecutive seasons (i.e., summer season of 2015 and off-season of 2016). The treatments used for the experiments contained 400 mg L−1 S-ABA applied at different timings of veraison (the onset of ripening), as follows: control (with no application); at pre-veraison (PRV); at veraison (V); and at post-veraison (POV). For all S-ABA treatments...

Ciência e Agrotecnologia, 2005

Com o presente trabalho teve-se como objetivo verificar o enraizamento de estacas de figueira ori... more Com o presente trabalho teve-se como objetivo verificar o enraizamento de estacas de figueira oriundas da desbrota, por meio da utilização de diferentes substratos. Foram coletadas estacas herbáceas de figueira 'Roxo de valinhos', aproximadamente com 10 cm de comprimento, no momento da desbrota da figueira. As estacas com apenas duas folhas e sem gema apical foram acondicionadas em bandejas de polipropileno, contendo diferentes substratos: casca de pinus®, vermiculita®, fibra de coco®, plantmax®, solo + esterco bovino (1:1 v/v) e tropstrato® . Posteriormente, as estacas foram colocadas em casa-de-vegetação, com umidade e temperatura controlada. Após 50 dias, avaliaram-se a porcentagem de estacas enraizadas, brotadas e mortas, número de folhas e raízes emitidas da estaca. Os substratos fibra de coco® e plantmax® promoveram melhores resultados.

The remainder of the six years of privatization and denationalization of Colombia Telecommunicati... more The remainder of the six years of privatization and denationalization of Colombia Telecommunications, has been a negative factor for Colombia and its citizens. The new foreign operator, Telefonica Internacional, failed to comply with its contractual obligations, its management and service are terrible, its financial results are negative and fur - thermore it has been saved by the Law on Capitalization, a government initiative, approved by the president of the Republic, thereby converting the Nation of Colombia into the custodian of oligopolistic transnational interests. Its nationalization will allow it to recover and to protect public patrimony, place it at the service of economic develop- ment, social progress and the well being of Colombians. The research undertaken has integrated historical and logic methodology, making use of primary sources such as interviews, laws, decrees, reports, opinions and judgments as well as secondary sources such as theses, assays and articles in add...

The Technologies of information and Communication (TIC), divides the microelectronics world into ... more The Technologies of information and Communication (TIC), divides the microelectronics world into computer science and telecommunications and they constitute a new technological revolution. In it for the first time, the backbone is the information and not the energy.

Diálogos de saberes, 2015

Los servicios públicos domiciliarios constituyen una categoría especial de los servicios públicos... more Los servicios públicos domiciliarios constituyen una categoría especial de los servicios públicos. Son bienes insustituibles, necesidades esenciales de la población ligadas a la existencia, calidad y dignidad de la vida humana y, en consecuencia, derechos fundamentales. Son una actividad económica. En este trabajo se cuestiona el modelo colombiano de prestación, regulación y control. Se utiliza un enfoque socio jurídico e interdisciplinario, un método teórico (análisis y síntesis) y se hace análisis documental.

Diálogos de saberes, 2013

La Teoría del Servicio Público desde sus orígenes en Francia en la segunda mitad del siglo XIX ha... more La Teoría del Servicio Público desde sus orígenes en Francia en la segunda mitad del siglo XIX hasta nuestros días, ha tenido una importante influencia en Colombia y en el mundo occidental. Se analizan sus orígenes, su naturaleza, evolución y vigencia, sus tendencias y sus contradicciones actuales, su práctica en el contexto internacional de las transformaciones ideológicas, políticas y económicas de las últimas tres décadas y su aplicación actual en las telecomunicaciones. Los elementos democráticos de la teoría del Servicio Público recobran vigencia para el rescate de lo público, de la prestación directa delos servicios públicos esenciales por parte del Estado, la utilización del derecho administrativo y la jurisdicción contencioso administrativa para resolver sus conflictos y como alternativa a las concepciones privatistas y mercantilistas predominantes. En la parte correspondiente de la investigación realizada, se integraron los métodos histórico y lógico, el análisis y la sínte...

Horticulturae, 2018

'BRS Vitoria' (Vitis spp.) is a novel hybrid seedless table grape recommended for cultivation in ... more 'BRS Vitoria' (Vitis spp.) is a novel hybrid seedless table grape recommended for cultivation in tropical and subtropical areas, especially for overseas export. The main postharvest disease of this cultivar is botrytis or gray mold (Botrytis cinerea), which occurs even under low temperatures in cold chambers. Sulfur dioxide (SO 2) release pads have been used to control this disease under cold storage, but some grape cultivars are sensitive to certain levels of this compound. The objective of this work was to evaluate different types of SO 2 generator pads in order to prevent the incidence of gray mold of 'BRS Vitoria' seedless grape, as well to avoid other grape injuries during cold storage. Grape bunches were harvested when fully ripened (16 • Brix) from a commercial field trained on overhead trellis and located at Marialva, state of Parana (PR) (South Brazil). Grapes were packed into carton boxes and subjected to the following SO 2 pad treatments (Uvasys ® , Cape Town, South Africa) in a cold chamber (2 • C): (a) control; (b) SO 2 slow release pad; (c) SO 2 dual release pad; (d) SO 2 dual release-fast reduced pad; (e) SO 2 slow release pad with grapes inoculated with B. cinerea; (f) SO 2 dual release pad with grapes inoculated with B. cinerea; and (g) SO 2 dual release-fast reduced pad with grapes inoculated with B. cinerea. After a 50-day cold chamber period, the grape boxes were kept for 7 days at room temperature at 25 • C. A randomized design was used with seven treatments and four replications, with five bunches per plot. The incidence of gray mold on grapes was evaluated after the 50-day cold storage and after the 7-days-at-room-temperature periods, as well other grape physicochemical variables, such as shattered berries, stem browning, bunch mass, bunch mass loss, skin color, soluble solids (SS), titratable acidity (TA), and SS/TA. The dual release pads were more efficient in preventing the incidence of gray mold and mass loss in 'BRS Vitoria' seedless grapes than the slow release pads in both storage periods. The incidence of shattered berries was lower when any type SO 2 pad was used during cold storage, and no effects were observed on stem browning, firmness, or berry skin color of 'BRS Vitoria' grapes.

Agronomy Science and Biotechnology, 2019

The objective of this work was to investigate the effect of the resistance inducer Acibenzolar-S-... more The objective of this work was to investigate the effect of the resistance inducer Acibenzolar-S-methyl (ASM), against Botrytis mold on table grapes in vitro and in vivo. To assess the effect of ASM on mycelial growth Botrytis cinerea, different concentrations (0.125, 0.25, 0.5, 1.0, 2.0 and 3% w:v) were tested. Treatments were set up in triplicate, in a completely randomized experimental design, and replicated twice. Results were expressed in minimum inhibitory concentrations and effective dose per 50% response of mycelial growth. Healthy table grapes (cvs. Italia and Benitaka) were harvested at full ripe to evaluate the ASM 1% effect against gray mold under artificial conditions. Bunches were split into two groups in order to perform two types of experiments (spray or immersion). For both trials, treated bunches were arranged in carton boxes and stored at 2±1 °C, for one month, followed by one week of shelf-life at 22±2 °C. In order to evaluate the ASM effect against gray mold und...

Agronomy Science and Biotechnology, 2018

Grape juices are blended in order to balance the organoleptic characteristics of juice, as well a... more Grape juices are blended in order to balance the organoleptic characteristics of juice, as well as to reduce off-season costs. The aim of this study was to evaluate the acceptance of consumers, through sensory analysis, of ‘Bordô’, ‘Niagara Rosada’, ‘BRS Nubia’ and ‘Isabel’ grape juices and their blends. The experiment was conducted during two periods. In the first, the grape juices analyzed were: ‘Niagara Rosada’ 100%, ‘Bordô’ 100%, ‘Isabel’ 100%, ‘Isabel’ 90% + ‘Bordô’ 10% and ‘Isabel’ 80% + ‘Bordô’ 20%. In the second, the following juices were evaluated: ‘Bordô’ 100%, ‘Niagara Rosada’ 100%, ‘Bordô’ 75% + ‘Niagara Rosada’ 25%, ‘Bordô’ 50% + ‘Niagara Rosada’ 50%, ‘Bordô’ 25% + ‘Niagara Rosada’ 75% and ‘BRS Nubia’ 100%. The juices were obtained by the ‘Welch’ process by steam entrainment. For the sensory evaluation, six tasters evaluated the following attributes in each period: color, aroma, flavor, body and overall acceptability, using a 7-point hedonic scale. The ‘Niagara Rosada’ ...

Agronomy, 2019

In colored table grapes, the anthocyanin contents are inhibited by the high temperature during ri... more In colored table grapes, the anthocyanin contents are inhibited by the high temperature during ripening and berries suffer a lack of skin color, thus affecting their market value. In order to overcome this issue, a research study was planned to evaluate the influence of (S)-cis-abscisic acid (S-ABA) on rates of anthocyanin accumulation in table grapes when applied at different timings of ripening, and to quantify the gradual increase of berry color. The study was conducted in a commercial vineyard of ‘Benitaka’ table grapes (Vitis vinifera L.), grown under double annual cropping system in a subtropical area. The trials were carried out during two consecutive seasons (i.e., summer season of 2015 and off-season of 2016). The treatments used for the experiments contained 400 mg L−1 S-ABA applied at different timings of veraison (the onset of ripening), as follows: control (with no application); at pre-veraison (PRV); at veraison (V); and at post-veraison (POV). For all S-ABA treatments...

Ciência e Agrotecnologia, 2005

Com o presente trabalho teve-se como objetivo verificar o enraizamento de estacas de figueira ori... more Com o presente trabalho teve-se como objetivo verificar o enraizamento de estacas de figueira oriundas da desbrota, por meio da utilização de diferentes substratos. Foram coletadas estacas herbáceas de figueira 'Roxo de valinhos', aproximadamente com 10 cm de comprimento, no momento da desbrota da figueira. As estacas com apenas duas folhas e sem gema apical foram acondicionadas em bandejas de polipropileno, contendo diferentes substratos: casca de pinus®, vermiculita®, fibra de coco®, plantmax®, solo + esterco bovino (1:1 v/v) e tropstrato® . Posteriormente, as estacas foram colocadas em casa-de-vegetação, com umidade e temperatura controlada. Após 50 dias, avaliaram-se a porcentagem de estacas enraizadas, brotadas e mortas, número de folhas e raízes emitidas da estaca. Os substratos fibra de coco® e plantmax® promoveram melhores resultados.