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Researchers at Universidad de Santiago represented Chile in important conferences on yeast biotechnology

Researchers at Universidad de Santiago represented Chile in important conferences on yeast biotechnology

  • Researchers at CECTA and DECYTAL at Universidad de Santiago successfully participated in two important scientific gatherings. They were the only Chileans participating in the 27th International Conference on Yeast Genetics and Molecular Biology and the 02nd International Specialized Symposium of Yeasts, held in the Italian cities of Levico and Perugia, respectively. Dr Verónica García Mena, Dr Claire Brice, Dr Claudio Martínez Fernández and Dr Francisco Cubillos Riffo presented their works at these conferences.

     

    Researchers at the Food Science and Technology Research Center (CECTA, in Spanish) and the Department of Food Science and Technology (DECYTAL, in Spanish) of Universidad de Santiago were the only Chilean representatives in two important scientific activities held in September, in Italy.

    The team led by Dr Claudio Martínez Fernández and made up of Dr Francisco Cubillos Riffo, Dr Verónica García Mena, and Dr Claire Brice presented the results of different studies conducted at the Applied Biotechnology and Microbiology Laboratory.

    The researchers participated in the 27th International Conference on Yeast Genetics and Molecular Biology, held between September 06th and 12th, in Levico, and the 02nd International Specialized Symposium of Yeasts, held between September 13th and 17th in Perugia, Italy.

    Strengthening links

    The director of CECTA, Dr Claudio Martínez, who is currently on a scientific-cultural exchange at the Instituto de Agroquímica y Tecnología de Alimentos (IATA, in Spanish) in Valencia, Spain, explained that the importance of these conferences lies on the possibility of “Strengthening links with the best researchers in this field worldwide, strengthening joint projects and opening opportunities to new collaborations and projects, as well as evaluating the level and the significance of what we are doing in Chile, that it is certainly very good at an international level.”

    For example, the team of CECTA is working on an international collaboration project with researchers at the IATA that also involves Argentinean researchers. And there is another international project with a French team that also participated in these conferences. This team is collaborating with a Fondecyt postdoctoral project and Dr Claire Brice is in charge of the last phase of this study.

    It is worth to mention that CECTA researchers were the only Chilean representatives in both conferences. According to professor Martínez, this was a surprise. And they were more surprised when they realized that, at a Latin American level, there were a few researchers from Argentina, Brazil and Uruguay. “This places us in a leading position at a national level and allows us to strengthen links with Latin American experts in this field to promote local and regional development,” he said.

    Leaders in yeast studies

    Yeasts were the common denominator in the conferences in which Universidad de Santiago researchers participated. Our university is leader in the area of yeast biotechnology in the country. “In this regard, the contributions made by our institution have turned into products (some of them have already been transferred to the productive sector in Chile and abroad) and specialized human resource training and have generated a worldwide renowned group of experts,” he concluded.

     

    Translated by Marcela Contreras

Study on lizards’ movements in granular environments could contribute to robotics

Study on lizards’ movements in granular environments could contribute to robotics

  • With the funding of a Fondecyt Postdoctoral Project 2016, Dr Baptiste Darbois, professor at the Faculty of Science of Universidad de Santiago, will be able to accurately determine how lizards move in granular soils in order to produce results that allow to create a robot able to move easily in different types of soil.

 

With the funding of a Fondecyt Postdoctoral Project 2016, Dr Baptiste Darbois, professor at the Faculty of Science of Universidad de Santiago, will be able to accurately determine how lizards move in granular soils in order to produce results that allow to create a robot able to move easily in different types of soil. This would mean a significant contribution to robotics.

Based on previous research that found that once lizards dive in the sand, they move by wriggling their bodies and not by using their legs, Dr Darbois will study the interaction between a vibrating elastic structure and the granular environment.

The Fondecyt Postdoctoral project (3160167) is called “Locomoción ondulatoria de nadadores suaves dentro de los medios granulares.”

Experimental challenge

The experimental challenge of the study is to control the movement of grains and the forces they undergo when lizards move. This would help to establish guidelines for developing robots able to adapt themselves to different environments. The way of moving of different animals has inspired engineers in this field.

“We expect the compression produced by lizards’ undulating movements in the desert’s sub-surface to help us to develop efficient robots by incorporating this mechanism,” Dr Darbois explained.

Likewise, professor Darbois intends to develop, in the long term, a robot based on the best features lizards show when moving in a granular environment.

“Through this project, we expect to define the optimal conditions: the dimensions, elasticity, frequency and amplitude of vibrations to move forward in waves through a granular environment,” the researcher said.

The relationship between lizards and the development of robots is not odd; on the contrary, it can benefit technological development and improve people´s quality of life. For example, it can be used in critical situations.

“With regard to its applications, developing robots able to efficiently move in granular environments could help to detect anti-personnel mines in the deserts and find people trapped under avalanches,” Dr Darbois concluded.

Translated by Marcela Contreras

Researchers at Universidad de Santiago develop bio-filter to adsorb copper from mining wastewaters

Researchers at Universidad de Santiago develop bio-filter to adsorb copper from mining wastewaters

  • A research team at the Faculty of Chemistry and Biology led by Dr Claudia Ortiz Calderón developed a device based on Chilean brown algae and pumice stone, which is able to adsorb copper from copper-bearing solutions produced by mining industry.

 

 

A research team at the Faculty of Chemistry and Biology led by Dr Claudia Ortiz Calderón developed a device based on Chilean brown algae and pumice stone, which is able to adsorb copper from copper-bearing solutions produced by mining industry.

Dr Ortiz, who is in charge of the Laboratory of Vegetable Biochemistry and Phytoremediation of the university, says that this study is part of the research that they usually conduct on the use of plants for environmental remediation.

Using this new device, it is possible to adsorb copper from copper-bearing streams to recover ions and send them back to the mining process, and clean the waters to use them again. Dr Ortiz says that they are already studying the effectiveness of the bio-filter with other metals, what could attract the interest of different companies.

Basically, the bio-filter is a vertical-flow column that contains three types of brown algae – which are very common in the Chilean coast- and pumice stone arranged in a way that is able to capture copper.

“First, we collect the algae and then, after washing, drying, chopping and screening them to a specific size, we package them together with pumicite or pumice stone that prevents the algae from getting compressed,” Dr Ortiz says.

She emphasizes that, in order no produce the bio-filter, they do not require to collect living biomass or to harvest algae. As they use waste algae and do not pre-treat the biomass, the bio-filter has a low cost of production. 

Patent request

The project started in 2012 and was funded by Corfo (the Chilean Economic Development Agent). It is currently at a protection stage after filing a patent request for the packaging system.

The next step is to continue with the analyses to determine the effectiveness of the bio-filter with other metals.

“We know that the bio-filter works very well for copper and we have also tested other equivalent cations, like zinc, cobalt and cadmium, and they have usually worked quite well too,” Dr Ortiz says.

“Thus, companies or industrial processes generating these elements which are interested in removing or recycling them could also be interested in the filter.”

In this context, the Canadian company Good Harbor that supported the project by conducting the hydraulic study of the columns has already expressed its interest in acquiring the rights of this new product.

Translated by Marcela Contreras

University receives recognition for its high number of patent requests filed

University receives recognition for its high number of patent requests filed

  • The National Institute of Industrial Property recognized Universidad de Santiago as the third Chilean university with the highest number of invention patent requests that seek to contribute to the country development in fields like chemistry and biology, engineering and technology. Maximiliano Santa Cruz, Inapi’s National Director and Óscar Bustos, Vice President of Research, Development and Innovation of Universidad de Santiago,   encouraged the University community to continue constantly producing industrial innovations to contribute to society.

On April 25th, in the context of the World Intellectual Property Day, our University was recognized as the third best national institution in requesting invention patents during 2013.

The National Institute of Industrial Property (Inapi, in Spanish)- an agency responsible to the Ministry of Economy in charge of registering, managing and promoting industrial property rights in Chile- granted our University an award in a ceremony led by Maximiliano Santa Cruz, Inapi´s National Director.

During the activity that took place at Inapi’s building, Santa Cruz highlighted the important role played by our University in producing creative innovations that contribute to our country’s development.

“Universidad de Santiago de Chile is absolutely essential to our patenting system. It has always been in the highest positions at the patent request ranking and this is not a coincidence: it is the result of serious intellectual property policies,” Inapi’s director said.

For Maximiliano Santa Cruz, our University’s interest in industrial property “is a powerful signal to its researchers, professors and innovators, in general.”

“I ask Universidad de Santiago’s innovators to continue creating new things and using the patenting system for it is a powerful tool to protect intellectual property,” he added.

Dr. Óscar Bustos, Vice President of Research, Development and Innovation (Vridei, in Spanish) of our University, who received Inapi´s award, showed himself very pleased with the position in the ranking at a national level.

“We are very satisfied with our exceptional position among the institutions that request for invention patents (…) We would have been happy to keep the second place like we did last year, but being among the main institutions that file patents requests in Chile is excellent news indeed,” Dr. Bustos said.

Pontifica Universidad Católica was at the first place in the patent request ranking while Universidad de Concepción was at the second place.

Finally, Vice President Bustos said that the high position of our University in the ranking reflects that “our researchers have become aware that not only scientific publications are important for our country: developing specific technological projects in key areas for Chile is important too.”

According to data provided by the Department of Technology Transfer of our University, during 2013, this state and public institution filed 11 invention patent requests in Chile, and at the same time, it filed other 42 requests with foreign agencies in charge of registering industrial inventions.

Translated by Marcela Contreras
 

Researchers study nanoparticles to prolong the effect of cancer-fighting drugs

Researchers study nanoparticles to prolong the effect of cancer-fighting drugs

  • In order to develop more tolerable therapies, a research team at the Faculty of Chemistry and Biology of Universidad de Santiago de Chile studies the use of biodegradable nanoparticles to increase the Adenosine Triphosphate (ATP) circulation time in the body to combat cancer.

 

In order to develop more tolerable therapies, a research team at the Faculty of Chemistry and Biology of Universidad de Santiago de Chile studies the use of biodegradable nanoparticles to increase the Adenosine Triphosphate (ATP) circulation time in the body to combat cancer.

The study is led by Dr Patricia Díaz, professor at the Faculty of Chemistry and Biology and is being developed in the context of the 2016 Fondecyt Post Doc Project (3160837) "Uso de nanopartículas con circulación prolongada para la administración de ATP en tratamientos anticancerígenos." Dr Díaz and her team will test new nanotechnology-based applications to deliver cancer-fighting drugs into the body.

She explains that any drug delivered in the body for therapeutic purposes requires a circulation time to play its therapeutic role.

Some molecules, like ATP, are quickly degraded, so high constant drug doses are required to be therapeutically effective and this is not beneficial for patients.

“As drugs are encapsulated in nanoparticles, the enzymes that metabolize them cannot bind to them. This is why they are protected against degradation. Consequently, drugs’ half-life is increased, prolonging its therapeutic efficacy,” she explains. 

Improved treatments

The advantage of using ATP as a cancer-fighting drug is that it has minor side effects if compared to other drugs. But ATP degrades very quickly when it is recognized by the enzymes in the body. Therefore, different drug administration methods are required, like the use of nanoparticles with biodegradable and biocompatible properties.

“For this reason, we want to encapsulate ATP into biocompatible nanoparticles to increase its half-life. We will also use other strategies to make them invisible to the immune system, so that they can circulate longer. The idea is to prevent them from binding to the cell and to avoid extracellular release of ATP. In this way, we expect to have a higher amount of drug available in the body for a prolonged anti-cancer effect,” she explains.

According to Dr Díaz, the main objective of the study is to test the effectiveness of ATP-carrying nanoparticles in cancer treatment. “I expect to demonstrate that nanoparticle-encapsulated drugs increase their bioavailability when compared with conventional administration methods. Besides, we also expect to analyze the potential synergistic effect of administrating ATP in combination with other drugs frequently used in cancer treatment.”

“This synergistic effect could destroy a higher number of cancer cells, benefiting patients with advanced cancer,” she adds.

Another advantage of this type of treatment is that, as it allows a sustained release of drugs in time, patients could receive the treatment once a week or every two or more weeks, depending on the drug encapsulation capacity and its circulation time,” she concludes. 

Dr Juan Pablo García-Huidobro, researcher at the Faculty of Chemistry and Biology, is also participating in the study, which is being conducted at the Pharmacology Laboratory.

 

Translated by Marcela Contreras



 

Universidad de Santiago opens new research building

Universidad de Santiago opens new research building

  • With a space of 2,755 m2, the five-floored building will be home to the Center for the Development of Nanoscience and Nanotechnology, the Aquaculture Biotechnology Center and the Soft Matter Center. The cost of the building construction amounted to about CLP 5,000 million.

 

 

In a context in which Chile only invests 0.39 of its GDP in research, the President of Universidad de Santiago de Chile, Dr Juan Manuel Zolezzi, highlighted the importance of this new space that will contribute to research and development in the country.

“This is one of the state-of-the arts buildings in Chile with regard to university research and it is an incentive for new researchers to continue innovating in key areas for the development of Chile,” he said. He added that Universidad de Santiago de Chile is a leader in technology transfer.

Senator Guido Girardi, who heads the Challenges for the Future. Science, Technology and Innovation Commission of the Upper House, valued the work done by public universities.

“These universities take charge of basic sciences on their own. Particularly, Universidad de Santiago has had the wisdom to connect basic sciences to the problems of the country and to generate innovation to solve these problems,” he said.

A few months ago, Dr Girardi visited the Center for the Development of Nanoscience and Nanotechnology (Cedenna, in Spanish) where he met with professionals in this significant research field. After the opening ceremony he congratulated the university on the new facilities.

The centers

Representatives of the centers that will occupy the new facilities expressed their satisfaction with the architectural configuration of the building that facilitates research development.

Dr Francisco Melo, Head of the Soft Matter Center that gathers together scientists in the fields of Physics, Chemistry, Biology and Engineering, said that the new space will offer endless opportunities for a better science development and for positioning the university at an international level.

For her part, Dr Dora Altbir, Head of the Cedenna, said that the possibility of bringing together scientists from different fields will allow a more active collaboration than the one that the university has now.

Eugenio Spencer Ossa, Head of the Aquaculture Biotechnology Center (CBA, in Spanish) said that the new building will allow to further scientific research and contribute to improve domestic industrial production, like salmon farming.

Architecture

The Rector Eduardo Morales Santos Research Building, with a total surface of 2,755.15 m2, is located in the central campus of the university. Its design is a geometric reinterpretation of the heritage buildings of the institution designed by the architects Héctor Valdés, Fernando Castillo Velasco, Carlos García Huidobro and Carlos Bresciani and built between 1957 and 1967. The building’s name is a tribute to the first democratically-elected university president after the dictatorship.

 

Translated by Marcela Contreras

New compound to prolong shelf life of dairy products

New compound to prolong shelf life of dairy products

  • The project led by Dr Silvia Matiacevich, professor at the Department of Food Science and Technology of the Technological Faculty, seeks to renew food industry by developing a compound with antimicrobial and antioxidant properties to prolong shelf life of dairy products. The project is funded through a Fondecyt Regular project 2016.

 

 

Nowadays, fresh, healthy and natural food consumption has increased, particularly, the intake of dairy products. According to the Chilean Bureau for Agricultural Studies and Policies (ODEPA; in Spanish), in 2013 the intake per capita was 146.5 liter, a national record in the country. 

However, these products require additives for their preservation that are not always natural and that do not allow a balanced and healthy diet.

In this context, Dr Silvia Matiacevich, professor at the Department of Food Science and Technology of the Technological Faculty; Dr Rubén Bustos, professor at the Department of Chemical Engineering of the Faculty of Engineering, and students at both units formed an interdisciplinary research team that will work on the study “Prolonged release of natural active compounds for improving shelf life of a dairy food matrix: Effect of structure obtained by different encapsulation process”. The project is funded by a Fondecyt Regular project (1160463) and it seeks to find a new active compound to preserve dairy products by means of nanotechnology. 

“We want to develop a new active ingredient with antimicrobial and antioxidant properties for dairy foods, in such a way that the compound has a prolonged release during storage, extending the product’s shelf life,” Dr Matiacevich says.

With this in mind, the researchers intend to study how the structure generated in this active ingredient- a powder developed through two different techniques- modifies its prolonged release in time in a real matrix,” she adds.

Food innovation and collaborative work

The objective of the study is to evaluate the effect of the structure obtained through “different encapsulation processes in prolonged release during storage of an encapsulated active agent,” in order to prolong the shelf life of a milk-based food matrix.

“By using encapsulation processes it is possible to obtain nanometric-sized particles, so the principles of nanotechnology are involved in this development,” favoring the compound prolonged release,” Dr Rubén Bustos, co-researcher of this study, says.

Food innovation research has increased worldwide. In Latin America, there are several research groups. For example, there are centers in Argentina, Colombia and Brazil, which professionals will collaborate in this project.

According to Dr Matiacevich, the main contribution of this study lies in that they will work directly with foods, so the study will not only provide basic knowledge but it will be applied to a real matrix.

For his part, Dr Bustos stresses the importance of their work with nanotechnology by saying: “At some point, microencapsulated ingredients were the greatest breakthrough, but now we will work with nanoencapsulated compounds, with much smaller and innovative structures.”

For the research team, the most important fact in relation to this project is that it involves the collaborative work of two departments of two different faculties of Universidad de Santiago de Chile. They also value the support of the Vice Presidency of Research, Development and Innovation, and the collaborative work with national and foreign universities. 

 

Translated by Marcela Contreras

Researchers at Universidad de Santiago develop hydrogen-based technology

Researchers at Universidad de Santiago develop hydrogen-based technology

  • Dr Daniel Serafini and Dr Álvaro San Martín, both professors at the Department of Physics, have developed an innovative solution that allows to store energy as hydrogen. One of the advantages of this technology is that it is not intermittent as current non-conventional energy sources (NCES), like solar and wind energy. This project is a contribution of Universidad de Santiago de Chile to the energy industry.

 

An innovative technology to store energy as hydrogen is being developed by Dr Daniel Serafini and Dr Álvaro San Martín, both professors at the Department of Physics of Universidad de Santiago de Chile.

According to Dr Serafini, one of the advantages of this technology is that it is not intermittent as current non-conventional energy sources (NCES), like solar and wind energy.

Hydrogen is generated during off-peak periods via water electrolysis. Then, depending on the needs, electric power is generated using the hydrogen stored in an electrochemical device called fuel cell. This system is very efficient and is environmentally friendly, because hydrogen combustion only generates water vapour, free of greenhouse gases and particulate matter.

Storing energy as hydrogen is a better solution in comparison to lithium batteries. “We compete with lithium batteries and they are much more expensive and heavier and they have technological problems regarding their size, i.e., at equal size, they have a more reduced capacity,” Dr Serafini says.

According to the expert, with current battery technology, lithium reserves in the world “are enough to cover only 40% of the cars in the Unites States.”

It is also worth to mention that this solution is particularly attractive to settlements in remote areas that do not receive power supply from the interconnected grid system.

The researchers implemented a demonstration module at the Minera San Pedro mining camp, in Til Til (at the north of the Metropolitan Region), where the pilot project has been working since mid-2015.

The CLP150 million project has been funded by the Innova Chile program of the Chilean Economic Development Agency (CLP132 million) and Minera San Pedro.

Greater involvement of the private sector

For his part, Dr San Martín stresses that the project has been well received by the Government and that now, a greater involvement of the private sector is required. “In developed countries, different public and private programs to develop hydrogen technologies have been funded with millions of dollars for a long time,” he says.

State-run bodies in Chile have already recognized the importance of hydrogen in the future for a clean non-polluting public transport. Both researchers agree that this is an essential starting point. 

Target market

One of the benefits of implementing this type of technology in Chile is that we have enormous ENCS resources of all kinds (solar, wind, geothermal, hydroelectric and tidal power), but they are intermittent, so the use of hydrogen would be highly convenient. 

The researchers say that this project “is not targeted at large companies for now, but remote places, like small settlements or fishing villages away from interconnected grid systems, little mine sites and road construction zones, etc.”

They expect to fully implement the project by mid-2016. Although they acknowledge that it is necessary to make this technology more price competitive, they say that costs have significantly fallen in recent times due to the huge development of fuel cell vehicles.

 

Translated by Marcela Contreras

Scientist works on mathematical model to prevent wooden structures from collapsing

Scientist works on mathematical model to prevent wooden structures from collapsing

  • Dr Erick Saavedra Flores, researcher at the Department of Civil Works Engineering of Universidad de Santiago de Chile, is studying new mathematical techniques to computer simulate the performance of wood at extreme ranges of deformation, cracking and ductile processes and its possible progressive collapse.

 

Wooden structures in a seismic country like Chile require constant inspection to check on its resistance in case of critical events such as earthquakes.

Dr Erick Saavedra Flores, researcher at the Department of Civil Works Engineering of Universidad de Santiago de Chile, is studying new mathematical techniques to computer simulate the performance of wood at extreme ranges of deformation, cracking and ductile processes and, eventually, in a progressive collapse.

Dr Saavedra explains that failures in wooden structures are divided into two groups: brittle and ductile failures. Both will determine the time before wood collapses. “Usually, structures fail abruptly, without previous notice. This type of failure is classified as ‘brittle’. However, at a local level, close to metal joints or fittings, wood fails in a “ductile” manner, i.e., it fails gradually in time. This latter type of failure is very common in very high buildings made of wood,” he says.

With the resources provided by a Fondecyt Regular project, Dr Saavedra will present a new model based on a mathematical technique called “homogenization”, which seeks to detect cracking and irreversible deformation processes at different spatial scales.

Worldwide efforts

“Achieving this goal will be a big challenge, because we require to extend the existing theory to incorporate the damage factor, i.e., degradation, loss of material stiffness and cracks into the multi-scale mechanical response of the material. In the past few years, big efforts have been made worldwide; however, predicting the mechanical performance of materials in this context remains to be a problem without a solution that is fully accepted by the scientific community,” he says.

He explains that he intends to incorporate this new material model to the advanced analysis of large-scale structures, because the big challenge posed by this goal is to computer simulate the progressive collapse of structures during seismic events.

In this regard, modeling this problem is extremely difficult as it involves extreme deformation processes, the interaction of elements that fall during the collapse process and their consequent fragmentation.

The project also considers experimental testing to validate the numerical predictions obtained during the study. Running these tests will be possible with the acquisition of a vibrating table for the Department of Civil Works Engineering.

As a final result of this study, the researcher expects to have material advanced models able to capture extreme deformation processes that allow to calculate ductility measures.

“I believe that the major impact my project may have is in the area of design and construction of buildings and large-scale structures. In the case of wood, particularly, it is possible to promote the use of radiata pine to construct tall buildings if we have a more precise knowledge of its performance during failures or eventual structural collapse,” Dr Saavedra explains. 

The study will be conducted in the context of the Fondecyt Regular project 2016 (1160691), “Advanced Modelling of Ductility and Damage in Mass Timber Structures by Computational Homogenization.”

 

Translated by Marcela Contreras

Study on lizards’ movements in granular environments could contribute to robotics

Study on lizards’ movements in granular environments could contribute to robotics

  • With the funding of a Fondecyt Postdoctoral Project 2016, Dr Baptiste Darbois, professor at the Faculty of Science of Universidad de Santiago, will be able to accurately determine how lizards move in granular soils in order to produce results that allow to create a robot able to move easily in different types of soil.

 

With the funding of a Fondecyt Postdoctoral Project 2016, Dr Baptiste Darbois, professor at the Faculty of Science of Universidad de Santiago, will be able to accurately determine how lizards move in granular soils in order to produce results that allow to create a robot able to move easily in different types of soil. This would mean a significant contribution to robotics.

Based on previous research that found that once lizards dive in the sand, they move by wriggling their bodies and not by using their legs, Dr Darbois will study the interaction between a vibrating elastic structure and the granular environment.

The Fondecyt Postdoctoral project (3160167) is called “Locomoción ondulatoria de nadadores suaves dentro de los medios granulares.”

Experimental challenge

The experimental challenge of the study is to control the movement of grains and the forces they undergo when lizards move. This would help to establish guidelines for developing robots able to adapt themselves to different environments. The way of moving of different animals has inspired engineers in this field.

“We expect the compression produced by lizards’ undulating movements in the desert’s sub-surface to help us to develop efficient robots by incorporating this mechanism,” Dr Darbois explained.

Likewise, professor Darbois intends to develop, in the long term, a robot based on the best features lizards show when moving in a granular environment.

“Through this project, we expect to define the optimal conditions: the dimensions, elasticity, frequency and amplitude of vibrations to move forward in waves through a granular environment,” the researcher said.

The relationship between lizards and the development of robots is not odd; on the contrary, it can benefit technological development and improve people´s quality of life. For example, it can be used in critical situations.

“With regard to its applications, developing robots able to efficiently move in granular environments could help to detect anti-personnel mines in the deserts and find people trapped under avalanches,” Dr Darbois concluded.

Translated by Marcela Contreras

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