Universidad Nacional de Mar del Plata (UNMdP)
URI permanente para esta comunidad
La Universidad Nacional de Mar del Plata (UNMdP), creada en 1975 posee 33 carreras de grado y 35 de posgrado.
EstĆ” formada por nueve facultades acadĆ©micas: Arquitectura, Urbanismo y DiseƱo, Ciencias Agrarias, Ciencias EconĆ³micas y Sociales, Ciencias Exactas y Naturales, Ciencias de la Salud y Servicio Social, Derecho, Humanidades, IngenierĆa, PsicologĆa. AdemĆ”s posee a su cargo el Colegio Nacional Dr. Arturo Illia, Ćŗnico secundario preuniversitario de la ciudad.
EstĆ” formada por nueve facultades acadĆ©micas: Arquitectura, Urbanismo y DiseƱo, Ciencias Agrarias, Ciencias EconĆ³micas y Sociales, Ciencias Exactas y Naturales, Ciencias de la Salud y Servicio Social, Derecho, Humanidades, IngenierĆa, PsicologĆa. AdemĆ”s posee a su cargo el Colegio Nacional Dr. Arturo Illia, Ćŗnico secundario preuniversitario de la ciudad.
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- ArtĆculo
Acceso Abierto Villa Gesell: un desequilibrio sedimentario inducido por fijaciones de mĆ©danos(AsociaciĆ³n Argentina de SedimentologĆa, 1998) Isla, Federico; BĆ©rtola, GermĆ”n R.; Farenga, Marcelo; Serra, Susana; Cortizo, Luis CamiloVilla Gesell fue construida sobre una barrera de mĆ©danos transversales a los vientos del SO. La fijaciĆ³n de estas dunas (plantaciones y forestaciones) alterĆ³ la morfologĆa original y la dinĆ”mica eĆ³lica, principalmente a partir de una disminuciĆ³n de la disponibilidad de arena que transformĆ³, en ciertos sectores, los mĆ©danos transversales en parabĆ³licos. Parte de la arena litoral fue a colmatar las depresiones intermedanosas dispuestas perpendicularmente a la lĆnea de costa. A partir de fotografĆas aĆ©reas se constatĆ³ que en el centro de Villa Gesell la lĆnea de ribera no ha retrocedido significativamente en 24 aƱos. SĆ³lo hacia el sur del partido, se reconoce la erosiĆ³n litoral debido indirectamente a la fijaciĆ³n de la barrera que produjo mĆ©danos frontales ( foredunes ) subalimentados. A travĆ©s de balances sedimentarios de cinco playas se reconocieron zonas de diferente dinĆ”mica. Las playas del norte poseen intercambios volumĆ©tricos significativamente menores que los del sur. Las arenas gruesas se deben a procesos de retrabajamiento de depĆ³sitos litorales fĆ³siles del sur. El transporte eĆ³lico selectivo, desde la playa hacia la barrera (inducido por las forestaciones), es tambiĆ©n causante de que en la playa dominen las granulometrĆas gruesas. - Comunicacion
Acceso Abierto Observaciones sobre la producciĆ³n y conservaciĆ³n de cebolla en el sudeste de Buenos Aires en relaciĆ³n con la disponibilidad hĆdrica(2007) Assuero, Silvia Graciela; Rattin, Jorge; Saluzzo, JosĆ©; Sasso, GastĆ³n; Tognetti, Jorge AlbertoEn experimentos con siete cultivares de cebolla de diferente longitud de ciclo, realizados en el sudeste de la provincia de Buenos Aires (Argentina) bajo restricciĆ³n hĆdrica, se observĆ³ ademĆ”s del esperable tamaƱo reducido de los bulbos, una llamativa desmejora en su conservaciĆ³n, en relaciĆ³n con ensayos sin limitaciones de agua. La marcada aceleraciĆ³n de la brotaciĆ³n y el incremento en la tasa de pĆ©rdida de peso de los bulbos en almacenamiento como consecuencia de las restricciones hĆdricas durante el llenado fueron confirmadas en un ensayo independiente con el cv. Valcatorce INTA. Estos resultados sugieren la necesidad de replantear el manejo del agua en cebolla al menos cuando se pretende su conservaciĆ³n a largo plazo, como es el caso de los cultivos para exportaciĆ³n. - ArtĆculo
Acceso Abierto ComparaciĆ³n de dos sistemas modernos de conducciĆ³n de cerezo (Prunus avium) en base a la eficiencia de intercepciĆ³n lumĆnica(2007) Godoy, Carlos; Tognetti, Jorge AlbertoLos sistemas de conducciĆ³n modernos de cerezos son diseƱados para maximizar la intercepciĆ³n lumĆnica y optimizar su distribuciĆ³n en el canopeo, y de esta manera incrementar la productividad y mejorar la calidad de los frutos. Se evaluaron dos sistemas: Eje Central (EC) con moderadamente alta densidad de plantaciĆ³n y Tatura Modificado (TM) con muy alta densidad, en tĆ©rminos de intercepciĆ³n de energĆa lumĆnica y distribuciĆ³n del Ć”rea foliar en el canopeo, en una plantaciĆ³n comercial durante dos temporadas consecutivas. El perfil de intercepciĆ³n de TM puso en evidencia una mayor iluminaciĆ³n en el centro de la doble fila con respecto a EC en el centro de la fila. La intercepciĆ³n a nivel del suelo fue de 21 % en EC y de 38 % en TM, habiĆ©ndose determinado un Ćndice de Ć”rea foliar (IAF) para EC de 2,02 y de 3,89 para TM. La eficiencia en la penetraciĆ³n de la luz en el canopeo fue mayor en TM que en EC. Al evaluar el diĆ”metro basal de las ramas laterales, los Ć”rboles conducidos en TM resultaron mĆ”s equilibrados. - ArtĆculo
Acceso Abierto Bacillus subtilis as a bioindicator to estimate pentachlorophenol toxicity and concentration(2009) Ayude, M. A.; Okada, E.; GonzĆ”lez, J. F.; Haure, P. M.; Murialdo, Silvia ElenaPentachlorophenol (PCP) and its sodium salt (Na-PCP) are extremely toxic chemicals responsible for important soil and groundwater pollution, mainly caused by wastes from wood-treatment plants, because chlorinated phenols are widely used as wood preservatives. The methods most commonly used for routine analysis of pesticides such as PCP and Na-PCP are high-performance liquid chromatography (HPLC) and gas chromatographyā mass spectroscopy (GCāMS). A variety of rapid biological screening tests using marine organisms, bioluminescent bacteria, and enzymes have also been reported. In this study, rapid biological screening analysis using Bacillus subtilis was developed, to assess the biodegradation of PCP and its by-products in liquid samples. An empirical model is proposed for spectrophotometric analysis of Na-PCP concentration after growth of Bacillus subtilis. - ArtĆculo
Acceso Abierto Analysis Of Bacterial Chemotactic Response Using Dynamic Laser Speckle(2009) Murialdo, Silvia Elena; Sendra, Gonzalo HernĆ”n; Passoni, LucĆa I.; Arizaga, Ricardo; Gonzalez, Jorge Froilan; Rabal, HĆ©ctor J.; Trivi, Marcelo RicardoChemotaxis has a meaningful role in several fields, such as microbial physiology, medicine and biotechnology. We present a new application of dynamic laser speckle or biospeckle to detect different degrees of bacterial motility during chemotactic response experiments. Encouraging results showed different bacterial dynamic responses due to differences in the hardness of the support in the swarming plates. We compare this method to a conventional technique that uses white light. Both methods showed to be analogous and, in some cases, complementary. The results suggest that biospeckle processed images can be used as an alternative method to evaluate bacterial chemotactic response and can supply additional information about the bacterial motility in different areas of the swarm plate assay that might be useful for biological analysis. - Documento de conferencia
Acceso Abierto Apoplastic hydrophobic proteins involved in tuber defense response to P. Infestans(2009) FernĆ”ndez, M.B; Daleo, Gustavo RaĆŗl; Guevara, M.G.; Pagano, M.R.During infection, oomycetes secrete effectors into the plant apoplast where they interact with host resistance proteins. In response, large amounts of protease and protease inhibitors (PIs), are accumulated. We analyzed differentially expressed Apoplastic Hydrophobic Proteins (AHPs) in potato tubers from Innovator (resistant) and Spunta (susceptible) cvs, after wounding and P. infestans infection. Intercellular washing fluid was extracted from control, wounded or infected tubers at 0, 24 and 48 h and chromatographed into a PepRPCtmHR5/5 in FPLC. After elution with acetonitrile, fractions were analyzed by SDS-PAGE and proteins identified by MALDITOF- MS. Innovator cv. showed a higher basal AHP content and hydrophobicity than Spunta cv. In the latter, infection induced accumulation of patatins and PIs, whereas in Innovator cv. no changes in PIs accumulation were observed. In response to P. infestans infection, lypoxigenase, enolase, annexin p34 and glutarredoxin/cyclophilin were accumulated in both cvs. Hydrophobicity of AHPs was higher after 24 h of wounding and infection in both cultivars. These results suggest that an increase in AHPs concentration would be related with the protection against the oomycete and with the degree of resistance to pathogens. Finally, changes in hydrophobicity of Pis may induce changes in proteaseinhibitor interaction affecting the defense response. - Documento de conferencia
Acceso Abierto Analysing the expression of genes associated with induced resistance in potato plants treated with phosphites(2009) Machinandiarena, M.F.; Feldman, M.; Daleo, Gustavo RaĆŗl; Andreu, A.B.Phosphites (Phi) have the ability to protect plants against different pathogens, both through a direct effect in oomycete metabolism and by an indirect effect stimulating the plantĀ“s natural defence responses. We have previously shown that KPhi foliar application to potato plants resulted in different protection levels against Phytophthora infestans depending on dose and plant age at application time. In order to identify genes that are involved in induced resistant in plants treated with KPhi, we analyzed by RT PCR, the time course of transcript levels of two genes which encode predicted transcription factors involved in pathogen perception and defence gene expression. Preliminary results showed that WRKY and NPR1 were differentially induced in plants both treated with Phi and infected with Phytophthora infestans, showing an earlier and highest induction than infected plants non treated with Phi. These results may allow us to hypothetize that Phi treatment might trigger a fast mechanism to protect potato plants to pathogen infections. - Documento de conferencia
Acceso Abierto Differentially expressed genes in potato sprouts after potassium phosphite application(2009) Feldman, M.; Machinandiarena, M.F.; Amarilla, L.D.; Guzzo, M.C.; Di Rienzo, J.; Daleo, Gustavo RaĆŗl; Andreu, A.B.We are studying the role of phosphites in disease control management, yield and potato tuber quality. In brief, our previous results showed a number of promising properties associated with these compounds. When we applied potassium phosphites (KPhi) at 3 litre $latex ha^{-1} $ to seed tubers immediately after cutting, this promoted early emergence, an increased in stem number and diameter, early tuber initiation and an increased in the number of tubers per plant. In addition to these physiological effects, phosphite treatment also resulted in greater resistance in seed tubers to Phytophthora infestans, Fusarium solani and Rhizoctonia solani. In order to understand the mechanisms which regulate these responses, we analyzed the changes in gene expression in tubers seeds at early stage of sprouting after KPhi treatment. Preliminary results of microarray analysis from potato sprouts treated or not with KPhi, showed that 26 genes were upregulated in the treated ones. These genes were classified into 5 groups: plant defense, metabolism, abiotic stress, transcription factors and unknown genes. We performed semiquantitative RT-PCR assays of some of these genes to validate the results. Interestingly one of these genes was CULLIN 1, involved in jasmonic acid mediated signaling pathway. This result may support the hypothesis that phophites could be involved in triggering IR (induced resistant). - ArtĆculo
Acceso Abierto Psychophysical estimation of acid intensity and determination of sweet-acid interaction in a fish paste containing glycerol(Sociedade Brasileira de CiĆŖncia e Tecnologia de Alimentos, 2010) Sanchez Pascua, Gabriela Leonor; Casales, MarĆa Rosa; Yeannes, MarĆa IsabelIn a fish paste made with cooked Brazilian flathead (Percophis brasiliensis), glycerol (17%), sodium chloride (1.5%) and potassium sorbate (0.1%) the following acid percentages: 0.2; 0.4; 0.6; 0.8, 1 and 1.5% w/w were incorporated to determine the relationship between added acetic acid and the sensorially perceived intensity, and the effects of the combination of sweet-acid tastes. Tests for paired comparison, ranking and structured verbal scales for sweet and acid attributes and psychophysical test were carried out. There was a perceptible difference among samples for differences of 0.4 units of acid concentration. Samples indicated as sweeter by 89.47% of the judges were those containing a lesser acid concentration. A reduction in glycerol sweetness when increasing acid levels was observed. Acetic acid reduced the sweetness of glycerol and inversely glycerol reduced the acidity of acetic acid. The data obtained with the magnitude estimation test agree with Stevenās law. - ArtĆculo
Acceso Abierto Functional Cytology of the Hepatopancreas of Palaemonetes argentinus (Crustacea, Decapoda, Caridea) Under Osmotic Stress(Instituto de Tecnologia do ParanĆ” - Tecpar, 2010) DĆaz, Ana Cristina; Sousa, Liliana Graciela; Petriella, Ana MarĆaThe present work describes the effect of different salinities on the functional morphology of the P. argentinus hepatopancreas and analyses the tissue recovery after re-acclimation to freshwater. Adult prawns of both sexes at sexual rest were collected from a tributary of the Mar Chiquita coastal lagoon. The prawns were acclimated in aquaria to four salinity conditions: 0 (control), 8, 16 and 24ā°. To evaluate the possible tissular recovery, after 60 days individuals from all the treatments were gradually acclimated to freshwater and maintained for other 30 days. Hepatopancreas samples were processed at the beginning of the trial and every 30 days using standard histological techniques for OM and TEM. The individuals from all the treatments, except the controls, showed a continuous weight decrease, and survival was lower when higher the salinity. At 30 days from the beginning of the experiment, hepatopancreas from 16 and 24ā° salinities showed an enlarged tubular lumen and an infolded basal lamina. Ultratructurally, nuclear retraction, cytoplasmolysis, and RER membranes separated with electron-dense content were observed in all the treatments except 0ā°. After 60 days, profound alterations were observed with the three treatments. After the re-acclimation period, there was no reestablishment of the functional cytology. The tolerance to short-term salinity changes explains the capability of this prawn to inhabit in estuarine environments. - Informe de investigador
Acceso Abierto Informe cientĆfico de investigador: Brizuela, Miguel Ćngel (2009-2011)(2011) Brizuela, Miguel ĆngelLas principales actividades de investigaciĆ³n desarrolladas (durante 2009-11) se enmarcan en el campo de las interacciones vegetaciĆ³n-herbĆvoros domĆ©sticos en distintos ambientes de pastoreo donde se desarrollan los sistemas de producciĆ³n animal de la RegiĆ³n Pampeana, y de otras regiones del paĆs. Los estudios buscan profundizar el conocimiento de caracterĆsticas estructurales y funcionales de pasturas naturales y cultivadas que condicionan el consumo y la integraciĆ³n de dietas por parte de animales en pastoreo en diferentes ecosistemas. En este perĆodo se continuĆ³ trabajandĆ³ en un proyecto cuyo objetivo es estudiar el proceso de selecciĆ³n de sitios de alimentaciĆ³n mediado por factores biĆ³ticos y abiĆ³ticos en tres regiones ganaderas de Argentina (Noreste Argentino, Pampa Deprimida Bonaerense y Patagonia Norte) con un subsidio FONCyT (NĀ°1488). Esos ecosistemas, a los cuales se sumĆ³ uno semiĆ”rido de New Mexico (EEUU), se sitĆŗan a lo largo de un gradiente de temperatura y humedad (escala espacial), lo que nos estĆ” permitiendo evaluar el peso relativo de factores biĆ³ticos y abiĆ³ticos en la distribuciĆ³n estacional del pastoreo de rodeos o majadas y su variaciĆ³n interanual (escala temporal). Para el desarrollo de estos estudios se utilizan de equipos de posicionamiento satelital (collares GPS) para el seguimiento de animales. En los sitios argentinos y el de NM se trabaja con una aproximaciĆ³n metodolĆ³gica similar para hacer compatible el anĆ”lisis de la informaciĆ³n. Se busca con esto alcanzar anĆ”lisis globales, que nos permitan pasar de la etapa actual de los estudios disponible en la bibliografĆa con fuerte Ć©nfasis local, a buscar patrones generales (universales) para el desarrollo de criterios de manejo mĆ”s amplios. Criterios referidos principalmente a ajustes de la carga y conducciĆ³n de los animales, de forma tal de lograr una eficiente utilizaciĆ³n de los recursos forrajeros, evitando procesos de degradaciĆ³n causados por prĆ”cticas de manejo incorrectas. - ArtĆculo
Acceso Abierto Multisubstrate Monod Kinetic Model for Simultaneous Degradation of Chlorophenol Mixtures(2011) Durruty, Ignacio; Okada, Elena; GonzƔlez, Jorge Froilan; Murialdo, Silvia ElenaChlorophenols (CPs) are persistent and highly toxic compounds rated as priority pollutants by the Environmental Protection Agency (EPA). Frequently, these compounds are present as mixtures of CPs in industrial wastewaters. Therefore the study of biodegradation on mixed pollutants is an important aspect of biodegradation and wastewater treatment. In this work, we studied the multisubstrate degradation of CPs by a mixed culture of Pseudomonas aeruginosa and a novel Acromobacter sp. capable of using pentachlorophenol (PCP), 2,4,6 trichlorophenol (2,4,6 TCP) and 2,3,5,6 tetrachlorophenol (2,3,5,6 TeCP) as the sole sources of carbon and energy. The main objective of this work was to evaluate the effect of substrate mixtures on the degradation kinetics of PCP. Batch experiments were conducted with each CP separately and in mixtures of PCP + 2,4,6 TCP, PCP + 2,3,5,6 TeCP, and PCP + 2,4,6 TCP + 2,3,5,6 TeCP. Based upon our results we have concluded that the simultaneous degradation of CPs is a key factor contributing to the improvement of PCP degradation. The kinetic parameters for PCP and 2,4,6 TCP were obtained by fitting the data to a Monod kinetics model. Using such parameters, the model was able to predict simultaneous multisubstrate degradation of PCP with others CPs. - Informe de investigador
Acceso Abierto Informe cientĆfico de investigador: Paredi, MarĆa Elida (2010-2011)(2011) Paredi, MarĆa ElidaEntre las temĆ”ticas principales comprendidas en el plan de invetigaciĆ³n y para el periodo que se informa se completaron los estudios, anĆ”lisis de resultados de la influencia de la conservaciĆ³n en almacenamiento congelado de calamar ( I argentinus) y la influencia del mĆ©todo de captura sobre las propiedades fisicoquĆmicas y funcionales de mĆŗsculo de aleta de calamar. - ArtĆculo
Acceso Abierto Effect of foliar applications of phosphite on post-harvest potato tubers(2011) Lobato, M.C.; Maschinandiarena, M.F.; Tambascio, C.; Dossio G.G.A.; Caldiz, D.; Daleo, Gustavo RaĆŗl; Andreu, A.B; Olivieri, F.P.The utilization of phosphites (Phi) could be considered as another strategy to be included in integrated disease management programmes to reduce the intensive use of fungicides and production costs. The aim of the present work was to analyze whether the beneficial effects of phosphite treatment previously observed in potato plants grown under greenhouse conditions, were reflected after harvest of field grown potatoes, both in disease protection and in yield. In addition, biochemical compounds possibly involved in induced defence responses by Phi, like phytoalexins, pathogenesis related proteins and oxidative stress enzymes were measured. Foliar applications of KPhi to field grown crops resulted in post-harvest tubers with a reduced susceptibility to Phytophthora infestans, Fusarium solani and Erwinia carotovora infections, suggesting that this compound induced a systemic defence response. An increase in phytoalexin content in P. infestans inoculated tubers obtained from Phi-treated plants suggests their participation in the defence response. Chitinase content increased 72h after wounding or inoculation with P. infestans in tubers from KPhi-treated plants compared to wounded or infected tubers from non-treated plants. Contrary to this, the isoforms of Ī²-1,3-glucanases analyzed did not increase in the tubers of Phi-treated plants. The increment in peroxidase and polyphenol oxidase activities indicated that these enzymes could be part of the Phi defence mechanism. No negative effects were observed in potato yield at harvest, measured as total tuber weight and dry matter, after foliar KPhi treatment. This suggests that the energetic cost involved in the defence response activation would not be detrimental to plant growth. - ArtĆculo
Acceso Abierto Cholesterol and membrane phospholipid compositions modulate the leakage capacity of the swaposin domain from a potato aspartic protease (StAPs-PSI).(2011) MuƱoz, F.F; Palomares-Jerez, M.F.; Daleo, Gustavo RaĆŗl; VillalaĆn, J.; Guevara, M.GPotato aspartic proteases (StAPs) and their swaposin domain (StAsp-PSI) are proteins with cytotoxic activity which involves plasma membrane destabilization. The ability of these proteins to produce cell death varies with the cellular type. Therefore, StAPs and StAsp-PSI selective cytotoxicity could be attributed to the different membrane lipid compositions of target cells. In this work we investigate the possible mechanism by which StAPs and StAsp-PSI produce selective membrane destabilization. Results obtained from leakage assays show that StAsp-PSI is a potent inducer of the leakage of LUVs containing anionic phospholipids, especially those containing phosphatidylglycerol. Based in these results, we suggest that the cytotoxic activity of StAsp-PSI on pathogenic microorganisms could be mediated by the attraction between the exposed positive domains of StAsp-PSI and the negatively charged microorganism membrane. On the other hand, our circular dichroism spectroscopic measurements and analysis by size exclusion chromatography and followed by electrophoresis, indicate that hydrophobic environment is necessary to StAsp-PSI oligomerization and both StAsp-PSI disulfide bounds and membrane with negative charged phospholipids are required by StAsp-PSI to produce membrane destabilization and then induce cell death in tumors and microorganism cell targets. Additionally, we demonstrate that the presence of cholesterol into the LUV membranes strongly diminishes the capacity of StAsp-PSI to produce leakage - ArtĆculo
Acceso Abierto Achromobacter marplatensis sp. nov., isolated from a pentachlorophenol contaminated soil(Microbiology Society, 2011) Gomila, Margarita; TvrzovĆ”, Ludmila; Teshim, Andrea; SedlĆ”ļek, Ivo; GonzĆ”lez Escalona, Narjol; ZdrĆ”hal, Zbynļk; Å edo, Ondrej; GonzĆ”lez, Jorge FroilĆ”n; Bennasar, Antonio; Moore, Edward R. B.; Lalucat, Jorge; Murialdo, Silvia ElenaA polyphasic taxonomic approach was applied to the study of a Gram-negative bacterium (B2T) isolated from soil by selective enrichment with pentachlorophenol. 16S rRNA gene sequence analysis of strain B2T showed that the strain belongs to the genus Achromobacter within the Betaproteobacteria. The 16S rRNA gene sequence displayed more than 99 % similarity to the sequences of the type strains of all species of Achromobacter, with the highest sequence similarity to those of Achromobacter spanius CCM 7183T and A. piechaudii CCM 2986T (99.8 %). On the basis of phylogenetic analysis, genomic DNAāDNA relatedness and phenotypic characteristics, including chemotaxonomic (cellular fatty acid profile) analysis, a novel species is proposed, Achromobacter marplatensis sp. nov., with the type strain B2T ( = CCM 7608T = CCUG 56371T = CECT 7342T). - ArtĆculo
Acceso Abierto Degradation of chlorophenol mixtures in a fed-Ābatch system by two soil bacteria(Water Research Commission, 2011) Durruty, Ignacio; Okada, Elena; GonzĆ”lez, Jorge FroilĆ”n; Murialdo, Silvia ElenaThis work was undertaken to investĆgate the effect of variations of the feed rate on a fed-batch set-up used to degrade xenobiotics. The mixture of substrates was composed of PCP, 2,4,6 TCP and 2,3,5,6 TeCP (pentachlorophenol, 2,4,6 trichlo- rophenol and 2,3,5,6 tetrachlorophenol respectively). Two acclimated bacteria isolated from soil were used: Pseudomonas aeruginosa and Achromobacter sp. nov. The different flow rates tested were: I: 0.5 ml*min-1, II: 1.67 ml*min$latex ^{} $-1 and III: 2.00 mf-min'1. Our results show that during fed-batch operation the 2,4,6 TCP exhibits an earlier degradation than the other com- pounds, for all of the flow rates tested. This indicates that in this case the degradation of the most recalcitrant compounds (PCP and 2,3,5,6 TeCP) is benefited by the increase in biomass ofbacteria, due to the metabolisation of a less recalcitrant compound (2,4,6 TCP). The defined parameter, specific degradation rate (SDR), was demonstrated to be very useful for comparing the degradation abilities at different flow rates of a fed-batch system. The degradation efficiencies were shown to be higher than 90% for all of the cases and to decrease as the feed rate increases. However, the SDR, a parameter that involves the rate of degradation and the biomass, increases as the flow rate increases. At a feed flow rate of 2 mf-min'1 SDR reaches a maximum of 12.476 x 10'10 mgCP-M-CFU'1. Finally, among the feed flows tested, taking into account both the degradation efficiency and the SDR, 2 ml-min-1 is the most convenient flow rate for chlorophenol degradation in fed-batch Systems. An even higher degradation efficiency (97%) can be achieved by using the feed rate of 2 mf-min'1 followed by an additional batch post-treatment of2 h, with a SDR of 13.136 x 10-10 mg CP-h1-CFU1. - Informe de personal de apoyo
Acceso Abierto Informe de personal de apoyo: Battistella, Diego (2011-2012)(2012) Battistella, DiegoProyectos de investigaciĆ³n en los cuales colabora: a) ColaboraciĆ³n con el Departamento de BiologĆa y Ciencias Marinas FCEyN. UNMDP. FĆŗnes 3350. 7600 Mar del Plata. Prov. De Buenos Aires. Argentina. TE: 54 223 475-6167. Fax: 54 223 475-3150, en los siguientes proyectos de investigaciĆ³n: 1)āFormaciĆ³n inicial de los esperamtĆ³foros en el testĆculo de Uca uruguayensis (BRACHYURA, OCYPODIDAE)ā. Cuartas, E. I. (1) y Petriella, A. M. (2), Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. (1) Departamento de BiologĆa. (2) Departamento de Ciencias Marinas. b) ColaboraciĆ³n con el Grupo EntomologĆa y AcarologĆa. Director: MartĆn Eguaras, Departamento de BiologĆa, Facultad de Ciencias Exactas y Naturales, UNMDP, en los siguientes proyectos de investigaciĆ³n: 1)āAceite esencial microencapsulado para el control de Loque americanaā. Fuselli, S., GarcĆa de la Rosa, S., Maggi, M., Ruffinengo, S. y Eguaras, M. - Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. - ArtĆculo
Acceso Abierto Effect of salinity changes on the midgut gland of Artemesia longinaris (Decapoda, Penaeidae)(Universidad CatĆ³lica de ValparaĆso, 2012) Masson, Ignacio; DĆaz, Ana Cristina; Petriella, Ana M.The response of the midgut gland of Artemesia longinaris to salinity changes was evaluated by analyzing its histological changes. Animals were exposed gradually and abruptly to 33, 29, 25 and 16 psu for different time intervals and readapted to 33 psu for 30 days. Individuals maintained 10 days at 16 psu showed the lowest survival and presented histopathologies which were not present in those readapted to 33 psu. Shrimps abruptly transferred from 33 to 16 psu died in 3-5 h but did not show midgut gland alterations likely due to the brief exposure. Only shrimps abruptly transferred from 33 to 25 psu presented histopathologies after 96 h. When readapted to 33 psu for 30 days, the midgut gland recovered an unaltered structure. Except E-cells, which did not vary in height among treatments, F, R and B-cells were taller in animals gradually adapted to 29 than to 16 psu. Abrupt salinity changes had a significant effect on the mean height of F, R and B-cells of those animals transferred from 33 to 25 psu (from 24 to 96 h after transfer F and R-cells heights decreased, and from 96 to 144 h after transfer B-cells height increased). Our study shows the effect of osmotic stress at the tissue level on the midgut gland and, at least partially, explains the reason for the mortalities at low salinities. - Informe de investigador
Acceso Abierto Informe cientĆfico de investigador: Tognetti, Jorge Alberto (2011-2012)(2012) Tognetti, Jorge Alberto1. ESPECIES FRUTALES DE CLIMA TEMPLADO: CRECIMENTO DE PLANTAS Y CALIDAD DE FRUTOS EN FUNCION DE VARIACIONES EN LA TEMPERATURA, INTENSIDAD DE LUZ y DISPONIBILIDAD DE NITROGENO a. Acerca de los efectos de diferentes Ć©pocas y modalidades de aplicaciĆ³n de fertilizantes nitrogenados en manzano, como resultantes de una tesis de Magister Scientiae (Ing. Agr. VerĆ³nica de Ćngelis): dirigida en un periodo anterior; b. Acerca de la fotosĆntesis y variables relacionadas en el cultivo de kiwi; c. Sobre la influencia de la temperatura de la planta y de los niveles de radiaciĆ³n fotosintĆ©ticamente activa sobre la calidad de los frutos de arĆ”ndano, se realizaron los ensayos previstos que forman parte de una tesis doctoral (Ing. Agr. Florencia Jaimes) en co-direcciĆ³n, que serĆ” presentada durante 2012; d. Acerca de la evaluaciĆ³n de mecanismos de resistencia al congelamiento en vides cv Malbec cultivadas bajo diferentes ambientes tĆ©rmicos, se participĆ³ de un proyecto de tesis doctoral (Ing. Agr. Francisco GonzĆ”lez Antivilo) en carĆ”cter de miembro del comitĆ© asesor. 2) ESPECIES HERBACEAS DE INTERES AGRONOMICO: PLASTICIDAD MORFO-FISIOLĆGICA Y CALIDAD DE LOS PRODUCTOS AGRĆCOLAS ANTE CAMBIOS EN TEMPERATURA, IRRADIANCIA Y NIVELES DE AZĆCARES a. Como resultado de una tesis de Ing. Agr. (GastĆ³n Sasso) realizada en un periodo anterior; b. Acerca de la capacidad germinativa de genotipos de girasol con composiciĆ³n acĆdica modificada; c. Acerca de los efectos de los cambios en temperatura e irradiancia en zanahoria; d. Sobre el rol de las citocininas en la promociĆ³n del desarrollo de follaje en Epipremnum aureum; e. En cuanto a respuestas morfofisiolĆ³gicas del trigo ante cambios en temperatura e irradiancia, parte de un proyecto de tesis doctoral (Lic. MĆ”ximo Lorenzo) a presentarse en 2012, bajo mi direcciĆ³n; f. Acerca de la tolerancia genĆ©tica para calidad industrial en trigo bajo estreses abiĆ³ticos asociados con el cambio climĆ”tico, se continuaron los trabajos correspondientes a un proyecto de tesis doctoral; g. Se iniciaron un proyecto de tesis doctoral sobre la relaciĆ³n entre filocrono y disponibilidad de asimilados (Ing. Agr. Cosme Paz, bajo mi direcciĆ³n) y uno de beca posdoctoral (Dra DĆ©bora PĆ©rez) sobre marcadores fisiolĆ³gicos de contaminaciĆ³n ambiental en plantas biomonitores (en co-direcciĆ³n).