13,328 research outputs found
Informe de personal de apoyo: Gortari, María Cecilia (2011-2012)
No full textProyectos de investigación en los cuales colabora:
a) Hongos autóctonos de posible interés económico: aislamiento, identificación, caracterización molecular y su potencial como productores de enzimas con implicancias biotecnológicas (PIP 112-200801-01422) del CONICET. Director: Dra. Angélica Arambarri. Co-director: Dr. Roque A. Hours.
b) Enzimas, microorganismos y procesos de interés biotecnológico. Acreditado y financiado por la SeCyT de la UNLP, código 11/X522. Años 2009-2012. Director: Dr. Roque Hours
Informe de personal de apoyo: Gortari, María Cecilia (2012-2013)
No full textProyectos de investigación en los cuales colabora:
a) Hongos autóctonos de posible interés económico: aislamiento, identificación, caracterización molecular y su potencial como productores de enzimas con implicancias biotecnológicas (PIP 112-200801-01422) del CONICET. Director: Dra. Angélica Arambarri. Co-director: Dr. Roque A. Hours.
b) Enzimas, microorganismos y procesos de interés biotecnológico. Acreditado y financiado por la SeCyt de la UNLP, código 11/X522. Años 2009-2012. Director: Dr. Roque A. Hours.
c) Proyecto de Investigación Plurianual (PIP 112-201101-00662) del CONICET: Microorganismos, enzimas y procesos biotecnológicos. Res. 1672/12. Años: 2012-2014
Price Competition, Business Hours, and Shopping Time Flexibility
No full textWe analyze differentiated retail industries where shops engage in two-stage competition with respect to opening hours and prices. We explore the effects of consumers' shopping time flexibility by comparing bi-directional consumers with forward- or backward-oriented consumers, who can either postpone or advance their shopping, but not both. We demonstrate that retailers with longer opening hours charge higher prices and that opening hour differentiation softens price competition. We calculate both symmetric and asymmetric subgame perfect equilibria in closing hours and demonstrate how the equilibrium configurations depend on the cost increases associated with extended business hours, as well as the relative densities of day and night shoppers. ZUSAMMENFASSUNG - (Preiswettbewerb, Öffnungszeiten und Flexibilität der Einkaufszeit) Wir analysieren unterschiedliche Einzelhandelsindustrien, in denen Läden in einem zweistufigen Wettbewerb bezüglich Öffnungszeiten und Preisen stehen. Wir erforschen die Effekte von Kundenflexibilität, indem wir völlig flexible Kunden mit vor- bzw. rückwärtsorientierten Kunden vergleichen können, welche ihren Einkauf nur vorziehen oder verschieben können, aber nicht beides. Wir zeigen, dass Einzelhändler mit längeren Öffnungszeiten höhere Preise verlangen und dass die Differenzierung der Öffnungszeiten den Preiswettbewerb abschwächt. Wir berechnen sowohl symmetrische als auch unsymmetrische teilspielperfekte Gleichgewichte für die Öffnungszeiten und zeigen, wie die Ausgestaltung der Gleichgewichte von den zusätzlichen Kosten der ausgedehnten Öffnungszeiten und der relativen Dichte von Tag- und Nachteinkäufern abhängt.Business Hours, Delayed or Advanced Shopping, Differentiated Business Hours, Price Competition, Shopping Time Flexibility.
Benefits of restricting alcohol trading hours
No full textResearch findings in Australia published in September 2016 - the first systematic review of alcohol trading hours and violence in more than five years - show that restricting alcohol trading hours can substantially reduce rates of violence and relaxing trading hours has the opposite effect.
"From reviewing the evidence, the message is clear - the more you restrict alcohol trading hours, the more you reduce violence," said lead author Claire Wilkinson from Melbourne's Centre for Alcohol Policy Research at La Trobe University.
The findings are "strong enough" for recommendations to governments to make restrictions on late trading hours and the weight of evidence - both Australian and international - demonstrates the effectiveness of restricting alcohol trading hours in combating violence.
According to the review, evidence from international studies was "compelling"
Sewing the Body of Christ : Eucharist wafer souvenirs stitched into fifteenth-century manuscripts, primarily in the Netherlands
No full textBooks of hours in the fifteenth century occupied several social and devotional roles. People used them to store small objects, including metal badges. Although the cultural practice of sewing in badges was widespread in the late Middle Ages, nearly all of the badges were removed (by later collectors). This article examines the practice by considering needle holes and offsets in the soft parchment, which indicate the shape of the badges and where they were attached. Noting that vast majority of metal offsets in books of hours are round, the author posits that these were not impressed by pilgrims’ badges, as is often repeated in the scholarly literature, but rather by tokens that commemorate having taken the Eucharist. The round badges are the same size and shape and bear the same imagery as host wafers. Owners stitched such badges into their books’ margins at locations relevant to Eucharistic piety. When they were sewn into books, Eucharist badges reconfigured the book as a shrine that recorded a votary’s pursuit of Communion.Peer reviewe
Reduction of l-phenylalanine in protein hydrolysates using l-phenylalanine ammonia-lyase from Rhodosporidium toruloides
No full textl-Phenylalanine ammonia-lyase (PAL, EC 4.3.1.25) from Rhodosporidium toruloides was utilized to remove l-phenylalanine (l-Phe) from different commercial protein hydrolysates. A casein acid hydrolysate (CAH, l-Phe ~2.28 %) was employed as a model substrate. t-Cinnamic acid resulting from deamination of l-Phe was extracted, analyzed at λ = 290 nm, and used for PAL activity determination. Optimum reaction conditions, optimized using successive Doehlert design, were 35 mg mL−1 of CAH and 800 mU mL−1 of PAL, while temperature and pH were 42 °C and 8.7, respectively. Reaction kinetics of PAL with CAH was determined under optimized conditions. Then, removal of l-Phe from CAH was tested. Results showed that more than 92 % of initial l-Phe was eliminated. Similar results were obtained with other protein hydrolysates. These findings demonstrate that PAL is a useful biocatalyst for l-Phe removal from protein hydrolysates, which can be evaluated as potential ingredients in foodstuffs for PKU patients.Fil: Castañeda, María Teresita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Adachi, Osao. Yamaguchi University; JapónFil: Hours, Roque Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentina. Universidad Tecnológica Nacional; Argentin
IN VITRO ACTIVITY OF PURPUREOCILLIUM LILACINUM ISOLATES AGAINST PHYTOPATHOGENIC FUNGI OF SORGHUM
No full textMetabolites produced by antagonist on the growthof phytopathogens fungus. The three P. lilacinumisolates had variable inhibitory activity accordingto the type of assay and phytopathogen evaluated.However, the inhibition was more evident with P.lilacinum Ls isolate and mainly with the effectof the non-volatile compounds. This studysuggests that P. lilacinum could be considered apromising antagonist in the control of Alternaria.These results motivate us to go deeper in theproduction, isolation and identification of thecompounds produced by this specie. The studiedP. lilacinum Ls isolate could be another tool in thedifferent biological control strategies applied tothe conservation of sorghum grains.Fil: Gortari, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Hours, Roque Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Astoreca, Andrea Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin
In vitro antagonistic activity of Argentinean isolates of Purpureocillium lilacinum on Nacobbus aberrans eggs
No full textIn vitro interaction of three Argentinean isolates of Purpureocillium lilacinum (one isolated from a public park and two from agricultural soils) towards Nacobbus aberrans eggs was studied. After seven incubation days, the three isolates showed reproductive fungal structures fully developed whereas 80 to 100 % of the eggs were infected. No significant differences among the three isolates were observed in fungal activity with respect to hatching and parasitism under the assayed test conditions (p > 0.05). The hatching percentage in control plates increased during the evaluation period of the cultures, with no signs of fungal infection, showing significant differences as compared to the plates infected (p < 0.05). Although the three isolates studied could be considered as potential agents for biological control of root-knot nematodes, it is necessary to further study some aspects in a wide range of experimental conditions in the laboratory, greenhouse and field so as to determine their real efficiency.Fil: Gortari, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Hours, Roque Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin
Biotechnological processes for chitin recovery out of crustacean waste: A mini-review
No full textAbstract Background: Chitin is an important natural resource. The annual worldwide production is estimated in approximately 1010-1012 ton. It is produced by arthropods (insects and crustaceans), molluscs and fungi. Its main biological function is structural. Crustacean shells are the most important chitin source for commercial use due to its high content and ready availability. Chitin and its derivatives have great economical value because of their numerous applications: food, cosmetics, pharmaceuticals, textile industries, waste water treatment and agriculture. In nature, chitin is closely associated with proteins, minerals, lipid and pigments, which have to be removed. Results: Several techniques to extract chitin from different sources have been reported. The most common method for recovery of chitin from crustacean shells is the chemical procedure. It involves two mayor steps: elimination of inorganic matter (demineralization) and extraction of protein matter (deproteination) using strong acids and bases. However, these processes may cause depolymerization affecting the polymer properties such as molecular weight, viscosity and degree of acetylation. In addition, the chemical purification of chitin is hazardous, energy consuming and threatening to the environment. As an alternative to the chemical process, different biological processes have been investigated: microbiological fermentation and methodologies using enzymatic crude extracts or isolated enzymes. Conclusions: The results reported are extremely variable; however, they offer new perspectives for the production of chitin with the concomitant reduction of the environmental impact.Fil: Hours, Roque Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales (i); ArgentinaFil: Gortari, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales (i); Argentin
Protopectinasa-se de Geotrichum klebahnii: Estudios de adsorción y capacidad de solubilización de pectina
No full textProtopectinasa-SE (PPasa-SE) es una poligalacturonasa producida por Geotrichum klebahnii con capacidad de liberar pectina por hidrólisis de protopectina. La reacción de liberación de pectina responde a un sistema de catálisis heterogenea, donde la interacción enzima-protopectina y la liberación de pectina, son objetivos de esta investigación. La interacción enzima-protopectina resultó dependiente del tamaño y estructura de las partículas del sustrato, así como de la naturaleza de la solución amortiguadora. Para partículas pequeñas la cinética de adsorción siguió un comportamiento definido por la isoterma de Langmuir. La reacción respondió al modelo cinético de Michaelis-Menten, con valores de Km y Vmax de 30.2 g/L y 57.3 g/L.h. Los mejores resultados en cuanto a la adsorción de la enzima y la solubilización de pectina fueron obtenidos con una solución amortiguadora de citrato y citrato-fosfato. Este trabajo constituye un primer reporte en cuanto a la solubilización de pectina que involucra un modelo de unión al sustrato asociado en sistemas pectinasa-protopectinasa.Protopectinase SE (PPase-SE) is a polygalacturonase produced by Geotrichum klebahnii with the capacity to liberate pectin through protopectin hydrolysis. The protopectin cleavage is a typical heterogeneous-catalysis reaction whose interaction between the enzyme and the protopectin substrate from lemon albedo along with the release of the pectin-reaction product were the objectives of this investigation. The interaction between PPase-SE and protopectin depended on the particle size and the structure of the substrate as well as on the nature of the buffer. The adsorption kinetics follows, for small particles, a Langmuir isotherm pattern. The reaction exhibited Michaelis-Menten kinetics, giving respective apparent-Km and Vmax values of 30.2 g/l and 57.3 g/l.h. The better results in enzyme adsorption and pectin releasing were obtained with citrate and citrate-phosphate buffers. This report constitutes the first investigation in pectin solubilization involving a model for the substrate-binding mechanism within the pectinase-protopectinase system.Fil: Zapata Zapata, Arley David. Universidad Nacional de Colombia; ColombiaFil: Hours, Roque Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Cavalitto, Sebastian Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin
- …
