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1. Face Recognition: to Deploy or not to Deploy? A Framework for Assessing the Proportional Use of Face Recognition Systems in Real-World Scenarios

Author

Negri, Pablo, Hupont, Isabelle, and Gomez, Emilia

Subjects
Computer Science - Computers and Society
Abstract

Face recognition (FR) has reached a high technical maturity. However, its use needs to be carefully assessed from an ethical perspective, especially in sensitive scenarios. This is precisely the focus of this paper: the use of FR for the identification of specific subjects in moderately to densely crowded spaces (e.g. public spaces, sports stadiums, train stations) and law enforcement scenarios. In particular, there is a need to consider the trade-off between the need to protect privacy and fundamental rights of citizens as well as their safety. Recent Artificial Intelligence (AI) policies, notably the European AI Act, propose that such FR interventions should be proportionate and deployed only when strictly necessary. Nevertheless, concrete guidelines on how to address the concept of proportional FR intervention are lacking to date. This paper proposes a framework to contribute to assessing whether an FR intervention is proportionate or not for a given context of use in the above mentioned scenarios. It also identifies the main quantitative and qualitative variables relevant to the FR intervention decision (e.g. number of people in the scene, level of harm that the person(s) in search could perpetrate, consequences to individual rights and freedoms) and propose a 2D graphical model making it possible to balance these variables in terms of ethical cost vs security gain. Finally, different FR scenarios inspired by real-world deployments validate the proposed model. The framework is conceived as a simple support tool for decision makers when confronted with the deployment of an FR system., Comment: Published a shorter version in IEEE International Conference on Automatic Face and Gesture Recognition 2024

Published
2024
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3. Shapes Characterization on Address Event Representation Using Histograms of Oriented Events and an Extended LBP Approach

Author

Negri, Pablo

Subjects
Computer Science - Computer Vision and Pattern Recognition
Abstract

Address Event Representation is a thriving technology that could change digital image processing paradigm. This paper proposes a methodology to characterize the shape of objects using the streaming of asynchronous events. A new descriptor that enhances spikes connectivity is associated with two oriented histogram based representations. This paper uses these features to develop both a non-supervised and a supervised multi-classification framework to recognize poker symbols from the Poker-DVS public dataset. The aforementioned framework, which uses a very limited number of events and a simple class modeling, yields results that challenge more sophisticated methodologies proposed by the state of the art. A feature family based on context shapes is applied to the more challenging 2015 Poker-DVS dataset with a supervised classifier obtaining an accuracy of 98.5 %. The system is also applied to the MNIST-DVS dataset yielding an accuracy of 94.6 % and 96.3 % on digit recognition, for scales 4 and 8 respectively.

Published
2018

5. Regional Commodities Price Volatility Assessment Using Self-driven Recurrent Networks

Author

Negri, Pablo, Ramos, Priscila, Breitkopf, Martin, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Tavares, João Manuel R. S., editor, Papa, João Paulo, editor, and González Hidalgo, Manuel, editor

Published
2021
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7. A Framework for Assessing Proportionate Intervention with Face Recognition Systems in Real-Life Scenarios

Author

Negri, Pablo, Hupont, Isabelle, Gomez, Emilia, Negri, Pablo, Hupont, Isabelle, and Gomez, Emilia

Abstract

Face recognition (FR) has reached a high technical maturity. However, its use needs to be carefully assessed from an ethical perspective, especially in sensitive scenarios. This is precisely the focus of this paper: the use of FR for the identification of specific subjects in moderately to densely crowded spaces (e.g. public spaces, sports stadiums, train stations) and law enforcement scenarios. In particular, there is a need to consider the trade-off between the need to protect privacy and fundamental rights of citizens as well as their safety. Recent Artificial Intelligence (AI) policies, notably the European AI Act, propose that such FR interventions should be proportionate and deployed only when strictly necessary. Nevertheless, concrete guidelines on how to address the concept of proportional FR intervention are lacking to date. This paper proposes a framework to contribute to assessing whether an FR intervention is proportionate or not for a given context of use in the above mentioned scenarios. It also identifies the main quantitative and qualitative variables relevant to the FR intervention decision (e.g. number of people in the scene, level of harm that the person(s) in search could perpetrate, consequences to individual rights and freedoms) and propose a 2D graphical model making it possible to balance these variables in terms of ethical cost vs security gain. Finally, different FR scenarios inspired by real-world deployments validate the proposed model. The framework is conceived as a simple support tool for decision makers when confronted with the deployment of an FR system., Comment: Submitted to the second revision round of IEEE Face and Gesture Recognition 2024

Published
2024

8. Sequential evacuation strategy for multiple rooms toward the same means of egress

Author

Parisi, Daniel R. and Negri, Pablo A.

Subjects
Physics - Physics and Society, Computer Science - Multiagent Systems
Abstract

This paper examines different evacuation strategies for systems where several rooms evacuate trough the same means of egress, using microscopic pedestrian simulation.As a case study, a medium-rise office building is considered. It was found that the standard strategy, whereby the simultaneous evacuation of all levels is performed, can be improved by a sequential evacuation, beginning with the lowest floor and continuing successively with each one of the upper floors after a certain delay. The importance of the present research is that it provides the basis for the design and implementation of new evacuation strategies and alarm systems that could significantly improve the evacuation of multiple rooms trough a common means of escape., Comment: 8 pages, 4 figures

Published
2014
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9. Spiking Hough for Shape Recognition

Author

Negri, Pablo, Serrano-Gotarredona, Teresa, Linares-Barranco, Bernabe, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Mendoza, Marcelo, editor, and Velastín, Sergio, editor

Published
2018
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10. A Citation k-NN Approach for Facial Expression Recognition

Author

Acevedo, Daniel, Negri, Pablo, Buemi, María Elena, Gómez Fernández, Francisco, Mejail, Marta, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Mendoza, Marcelo, editor, and Velastín, Sergio, editor

Published
2018
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12. Extended LBP Operator to Characterize Event-Address Representation Connectivity

Author

Negri, Pablo, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Beltrán-Castañón, César, editor, Nyström, Ingela, editor, and Famili, Fazel, editor

Published
2017
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13. Pedestrian Detection Using Multi-Objective Optimization

Author

Negri, Pablo, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, and Pardo, Alvaro, editor

Published
2015
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14. Modeling Video Activity with Dynamic Phrases and Its Application to Action Recognition in Tennis Videos

Author

Vainstein, Jonathan, Manera, José F., Negri, Pablo, Delrieux, Claudio, Maguitman, Ana, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Kobsa, Alfred, Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Bayro-Corrochano, Eduardo, editor, and Hancock, Edwin, editor

Published
2014
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18. Pedestrian Detection Using a Feature Space Based on Colored Level Lines

Author

Negri, Pablo, Lotito, Pablo, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Alvarez, Luis, editor, Mejail, Marta, editor, Gomez, Luis, editor, and Jacobo, Julio, editor

Published
2012
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19. A Multi-style License Plate Recognition System Based on Tree of Shapes for Character Segmentation

Author

Gómez Fernández, Francisco, Negri, Pablo, Mejail, Marta, Jacobo, Julio, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, San Martin, César, editor, and Kim, Sang-Woon, editor

Published
2011
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21. Multiple Clues for License Plate Detection and Recognition

Author

Negri, Pablo, Tepper, Mariano, Acevedo, Daniel, Jacobo, Julio, Mejail, Marta, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Bloch, Isabelle, editor, and Cesar, Roberto M., Jr., editor

Published
2010
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23. Multi-class Vehicle Type Recognition System

Author

Clady, Xavier, Negri, Pablo, Milgram, Maurice, Poulenard, Raphael, Carbonell, Jaime G., editor, Siekmann, J\'org, editor, Prevost, Lionel, editor, Marinai, Simone, editor, and Schwenker, Friedhelm, editor

Published
2008
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25. A New Voting Algorithm for Tracking Human Grasping Gestures

Author

Negri, Pablo, Clady, Xavier, Milgram, Maurice, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Blanc-Talon, Jacques, editor, Philips, Wilfried, editor, Popescu, Dan, editor, and Scheunders, Paul, editor

Published
2005
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26. SL-Animals-DVS: event-driven sign language animals dataset

Author

European Commission, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Economía y Competitividad (España), Universidad de Buenos Aires, Asociación Universitaria Iberoamericana de Postgrado (España), Vasudevan, Ajay, Negri, Pablo, Di Ielsi, Camila, Linares-Barranco, Bernabé, Serrano-Gotarredona, Teresa, European Commission, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Economía y Competitividad (España), Universidad de Buenos Aires, Asociación Universitaria Iberoamericana de Postgrado (España), Vasudevan, Ajay, Negri, Pablo, Di Ielsi, Camila, Linares-Barranco, Bernabé, and Serrano-Gotarredona, Teresa

Abstract

Non-intrusive visual-based applications supporting the communication of people employing sign language for communication are always an open and attractive research field for the human action recognition community. Automatic sign language interpretation is a complex visual recognition task where motion across time distinguishes the sign being performed. In recent years, the development of robust and successful deep-learning techniques has been accompanied by the creation of a large number of databases. The availability of challenging datasets of Sign Language (SL) terms and phrases helps to push the research to develop new algorithms and methods to tackle their automatic recognition. This paper presents ‘SL-Animals-DVS’, an event-based action dataset captured by a Dynamic Vision Sensor (DVS). The DVS records non-fluent signers performing a small set of isolated words derived from SL signs of various animals as a continuous spike flow at very low latency. This is especially suited for SL signs which are usually made at very high speeds. We benchmark the recognition performance on this data using three state-of-the-art Spiking Neural Networks (SNN) recognition systems. SNNs are naturally compatible to make use of the temporal information that is provided by the DVS where the information is encoded in the spike times. The dataset has about 1100 samples of 59 subjects performing 19 sign language signs in isolation at different scenarios, providing a challenging evaluation platform for this emerging technology.

Published
2022

40. Scene Context Classification with Event-Driven Spiking Deep Neural Networks

Author

Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores, European Union (UE), Ministerio de Economía y Competitividad (MINECO). España, Negri, Pablo, Soto, Miguel, Linares Barranco, Bernabé, Serrano Gotarredona, María Teresa, Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores, European Union (UE), Ministerio de Economía y Competitividad (MINECO). España, Negri, Pablo, Soto, Miguel, Linares Barranco, Bernabé, and Serrano Gotarredona, María Teresa

Abstract

Event-Driven computation is attracting growing attention among researchers for several reasons. On one hand, the availability of new bio-inspired retina-like vision sensors that provide spiking outputs, like the Dynamic Vision Sensor (DVS) make it possible to demonstrate energy efficient and highspeed complex vision tasks. On the other hand, the emergence of abundant new nanoscale devices that operate as tunable two-terminal resistive elements, which when operated through dynamic pulsing techniques emulate learning and processing in the brain, promise an explosion of highly compact energy efficient neuromorphic event-driven applications. In this paper we focus for the first time on a high-level cognitive task, namely scene context classification, performed by event-driven computations and using real sensory data from a DVS camera.

Published
2018

41. Pedestrian tracking using probability fields and a movement feature space

Author

Negri, Pablo and Garayalde, Damián

Subjects
espacio de descriptores dinámicos, pedestrian tracking, target framework, movement feature space, seguimiento de peatones
Abstract

Retrieving useful information from video sequences, such as the dynamics of pedestrians, and other moving objects on a video sequence, leads to further knowledge of what is happening on a scene. In this paper, a Target Framework associates each person with an autonomous entity, modeling its trajectory and speed by using a state machine. The particularity of our methodology is the use of a Movement Feature Space (MFS) to generate descriptors for classifiers and trackers. This approach is applied to two public sequences (PETS2009 and TownCentre). The results of this tracking outperform other algorithms reported in the literature, which have, however, a higher computational complexity. Resumen Recuperar información de secuencias de video, como la dinámica de peatones u otros objetos en movimiento en la escena, representa una herramienta indispensable para interpretar que está ocurriendo en la escena. Este artículo propone el uso de una Arquitectura basada en Targets, que asocian a cada persona una entidad autónoma y modeliza su dinámica con una máquina de estados. Nuestra metodología utiliza una familia de descriptores calculados en el Movement Feature Space (MFS) para realizar la detección y seguimiento de las personas. Esta arquitectura fue evaluada usando dos bases de datos públicas (PETS2009 y TownCentre), y comparándola con algoritmos de la literatura, arrojó mejores resultados, aun cuando estos algoritmos poseen una mayor complejidad computacional.

Published
2017

43. Spiking Hough for Shape Recognition

Author

Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores, European Union (UE), Ministerio de Economía y Competitividad (MINECO). España, Negri, Pablo, Serrano Gotarredona, María Teresa, Linares Barranco, Bernabé, Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores, European Union (UE), Ministerio de Economía y Competitividad (MINECO). España, Negri, Pablo, Serrano Gotarredona, María Teresa, and Linares Barranco, Bernabé

Abstract

The paper implements a spiking neural model methodology inspired on the Hough Transform. On-line event-driven spikes from Dynamic Vision Sensors are evaluated to characterize and recognize the shape of Poker signs. The multi-class system, referred as Spiking Hough, shows the good performance on the public POKER-DVS dataset.

Published
2017

49. Effect of postharvest treatments on the expression of HSPs in tomatoes Beatriz

Author

Guidi, Silvina M., Nanni, Mariana Sandra, Budde, Carlos Ernesto, Negri, Pablo Augusto, Polenta, Gustavo Alberto, and Gonzalez, Claudia Beatriz

Subjects
Tomate, CIENCIAS AGRÍCOLAS, Agricultura, purl.org/becyt/ford/4.1 [https], Desorden fisiológico, Poscosecha, Solanum lycopersicum L, Agricultura, Silvicultura y Pesca, purl.org/becyt/ford/4 [https], Tratamiento termico, Estrés
Abstract

El almacenamiento de frutos de tomates (Solanum lycopersicum L.) a bajas temperaturas permite extender el período de mercadeo. Sin embargo, esta fruta es susceptible de manifestar daño por frío (DF). El objetivo del presente trabajo fue estudiar la expresión de dos familias de proteínas de estrés térmico (HSPs) en muestras de tomates Beatriz sometidas a diferentes tratamientos térmicos poscosecha: 1) Tratamiento térmico corto (inmersión 60 min a 42 °C) = HS60m; 2) tratamiento térmico largo (incubación en cámara 24 h a 39 °C) = HS24h; y 3) no tratados, utilizados como control (C). La fruta fue analizada en tres diferentes períodos: en la cosecha (control), luego de aplicado el tratamiento térmico (0), y luego de 1 h de exposición a temperatura ambiente (+1h). Por la técnica de SDS-PAGE se observó que ambos tratamientos indujeron la síntesis de una proteína con peso molecular aparente de 21 kDa. Sin embargo, no se observaron cambios en la región de 70 kDa. La sobreexpresión de las HSPs fue evaluada por la técnica de Western blot, usando un anticuerpo policlonal anti-sHSPs realizado contra la principal proteína de tomates tratados térmicamente (HSPC1) y un anticuerpo anti-HSP70 comercial. El antisuero HSPC1 detectó la presencia de una proteína de 21 kDa, especialmente en las muestras sometidas al tratamiento largo (HS24h). Sin embargo, no se encontraron diferencias en la expresión de las muestras sometidas al tratamiento corto (HS60m) y el control. El anticuerpo anti-HSP70 detectó una proteína de 70 kDa sólo en las muestras sometidas al tratamiento HS24h. Entre los tratamientos ensayados, el tratamiento térmico largo (HS24h) fue el más efectivo en inducir ambas familias de HSPs. Storage of tomatoes (Solanum lycopersicum L.) at low temperature allows to extend the marketing period. However, these fruit are susceptible to suffer chilling injury (CI). The aim of this work was to study the expression of two families of heat shock proteins (HSPs) in tomato samples submitted at different postharvest heat treatments. The treatments assayed were: 1) short heat treatment (immersion for 60 min at 42 °C) = HS60m; 2) long heat treatment (incubation in chamber 24 h at 39°C) = HS24h; and 3) no treatment, control (C). The fruit was analyzed at three different periods: at harvest (control), at the end of heat treatment (0), and after 1 h the exposition at room temperature (+1h). Both treatments induced the synthesis of one protein with apparent molecular mass of 21 kDa, observed by SDS-PAGE technique. No changes were observed at the 70 kDa region. The overexpression of HSPs was evaluated by western blot, using a sHSP-specific polyclonal antiserum raised against the main sHSPs from heated tomatoes (HSPC1) and a monoclonal antiserum raised against HSP70. The HSPC1 detected the accumulation of one prevalent protein with MW of 21 kDa, especially in the long treated samples (HS24h). There was no difference observed between samples submitted to HS60m and the control ones. The monoclonal HSP70 antiserum detected a 70 kDa protein only in HS24h samples. Among the treatments assayed, HS24h was more effective to induce both families of HSPs. Fil: Guidi, Silvina M.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina Fil: Nanni, Mariana Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina Fil: Budde, Carlos Ernesto. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria San Pedro; Argentina Fil: Negri, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Universidad Argentina de la Empresa; Argentina Fil: Polenta, Gustavo Alberto. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina Fil: Gonzalez, Claudia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina

Published
2015

50. Efecto de los tratamientos poscosecha en la expresión de proteínas de estrés térmico en tomate Beatriz = Effect of postharvest treatments on the expression of HSPs in tomatoes Beatriz

Author

Guidi, Silvina Mabel, Nanni, Mariana, Budde, Claudio Olaf, Negri, Pablo Augusto, Polenta, Gustavo Alberto, and Gonzalez, Claudia Beatriz

Subjects
Control de Plagas (Postcosecha), Estrés Térmico, Heat Stress, Trastornos Funcionales, Postharvest Control, Solanum Lycopersicum, Tratamiento Postcosecha, Physiological Disorders, Proteins, Functional Disorders, Postharvest Treatment, Tomate, Tomatoes, Proteínas
Abstract

El almacenamiento de frutos de tomates (Solanum lycopersicum L.) a bajas temperaturas permite extender el período de mercadeo. Sin embargo, esta fruta es susceptible de manifestar daño por frío (DF). El objetivo del presente trabajo fue estudiar la expresión de dos familias de proteínas de estrés térmico (HSPs) en muestras de tomates Beatriz sometidas a diferentes tratamientos térmicos poscosecha: 1) Tratamiento térmico corto (inmersión 60 min a 42 °C) = HS60m; 2) tratamiento térmico largo (incubación en cámara 24 h a 39 °C) = HS24h; y 3) no tratados, utilizados como control (C). La fruta fue analizada en tres diferentes períodos: en la cosecha (control), luego de aplicado el tratamiento térmico (0), y luego de 1 h de exposición a temperatura ambiente (+1h). Por la técnica de SDS-PAGE se observó que ambos tratamientos indujeron la síntesis de una proteína con peso molecular aparente de 21 kDa. Sin embargo, no se observaron cambios en la región de 70 kDa. La sobreexpresión de las HSPs fue evaluada por la técnica de Western blot, usando un anticuerpo policlonal anti-sHSPs realizado contra la principal proteína de tomates tratados térmicamente (HSPC1) y un anticuerpo anti-HSP70 comercial. El antisuero HSPC1 detectó la presencia de una proteína de 21 kDa, especialmente en las muestras sometidas al tratamiento largo (HS24h). Sin embargo, no se encontraron diferencias en la expresión de las muestras sometidas al tratamiento corto (HS60m) y el control. El anticuerpo anti-HSP70 detectó una proteína de 70 kDa sólo en las muestras sometidas al tratamiento HS24h. Entre los tratamientos ensayados, el tratamiento térmico largo (HS24h) fue el más efectivo en inducir ambas familias de HSPs. Storage of tomatoes (Solanum lycopersicum L.) at low temperature allows to extend the marketing period. However, these fruit are susceptible to suffer chilling injury (CI). The aim of this work was to study the expression of two families of heat shock proteins (HSPs) in tomato samples submitted at different postharvest heat treatments. The treatments assayed were: 1) short heat treatment (immersion for 60 min at 42 °C) = HS60m; 2) long heat treatment (incubation in chamber 24 h at 39°C) = HS24h; and 3) no treatment, control (C). The fruit was analyzed at three different periods: at harvest (control), at the end of heat treatment (0), and after 1 h the exposition at room temperature (+1h). Both treatments induced the synthesis of one protein with apparent molecular mass of 21 kDa, observed by SDS-PAGE technique. No changes were observed at the 70 kDa region. The overexpression of HSPs was evaluated by western blot, using a sHSP-specific polyclonal antiserum raised against the main sHSPs from heated tomatoes (HSPC1) and a monoclonal antiserum raised against HSP70. The HSPC1 detected the accumulation of one prevalent protein with MW of 21 kDa, especially in the long treated samples (HS24h). There was no difference observed between samples submitted to HS60m and the control ones. The monoclonal HSP70 antiserum detected a 70 kDa protein only in HS24h samples. Among the treatments assayed, HS24h was more effective to induce both families of HSPs. Instituto de Tecnología de los Alimentos Fil: Guidi, Silvina Mabel. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina Fil: Nanni, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina Fil: Budde, Claudio Olaf. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; Argentina Fil: Negri, Pablo Augusto. Universidad Argentina de la Empresa. Instituto de Tecnología; Argentina Fil: Polenta, Gustavo Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina Fil: Gonzalez, Claudia Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Published
2015

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